The combined effect of marble powder and polypropylene fibre on the properties of self-compacting repair mortar

Abstract

Durability and service life of structures are guaranteed towards the reparation and rehabilitation of concrete. Repair materials are usually cementitious matrixes reinforced with fibres. Partial replacement of cement by supplementary cementitious materials in repair products is important to decrease the consuming of cement, conserve natural resources, reduce waste as well as assisted to advanced sustainable building materials. For this purpose, six self-compacting repair mortar (SCRM) reinforced by polypropylene fibre (PPF) were prepared with replacement of cement by marble powder (MP) at different percentages 0%, 10%, 15%, 20%, 25% and 30% according to the EFNARC 2005 specifications. First, the optimization of fibre’s dosage is obtained at fresh and hardened states (compressive and flexural strength) at 28 days. Then, SCRM reinforced by polypropylene fibres was evaluated in different methods, at fresh states (slump flow) and hardened states (compressive and flexural strength and elasticity modulus) at 3, 7, 28 and 90 days. In addition, durability was studied on sorptivity at 28 days and adhesion strength on composite specimens (half SCRM/half substrate mortar) at 7, 28 and 90 days. The obtained results of fresh mortar revealed that the addition of PPF contributed to workability enhancement. The combined use of PPF and MP showed good mechanical properties of SCRM which fulfilling the requirements of class R4 materials for structural repair products. On the other side, elasticity modulus has decreased with the increment of marble powder content however, a good correlation is attained between elasticity modulus and compressive strength. Adhesion test indicated that 15% of MP is the optimum dosage which provides 20% of gain in adhesion strength.

Keywords

Repair mortar marble powder polypropylene fibre adhesion compatibility

Introduction

Concrete structures inspections and maintenance are an important uninterrupted process to ensure the preservation of structural integrity during its lifetime. Most structures would require minor repairs; however, some of them need major intervention. Structures damage is caused through several factors such as change in function, increase in loads, changes in the building regulations and sometimes the mistakes in execution or chemical attacks.^1–4 These factors require either repair or reinforcement interventions. In addition to that, the damage caused by fire, earthquake and any other deterioration resulting from a natural or human phenomenon otherwise from ageing of the structure. The suitable solution in this situation is to repair or reinforce the structures rather than demolish and rebuild them. According to ACI Committee 2016,⁵ concrete durability is defined as the ability to withstand the action of weathering and other deterioration processes throughout retaining serviceability when it is exposed to the intended service environment.

Due to the brittle nature of concrete and mortar, the use of fibre is indispensable and has numerous important effects on enhancing the toughness of the material and its precracking behaviour. Fibres are available in a variety of sizes, shapes, and materials. They can be made of steel,^6,7 plastic,⁸ glass,⁹ and natural materials.¹⁰ Many researchers reported that the incorporation of fibres into the mix can improve mechanical and ductile behaviour of the material.^11,12 Hassan et al.¹³ revealed that hybridization of polypropylene fibres led to 15% of shrinkage reduction. However, Zhang and Li¹⁴and Tabatabaeian et al.¹⁵ showed that adding fibre to mortar mix reduced its slump flow.

The use of composite materials including carbon fibre, aramid, basalt, glass fibre and polypropylene fibre for structural reinforcement, load-bearing and containment is a proven technique. The addition of fibres to reinforce repair materials have gained recently more attention.^16,17 Some researchers studied the effect of polyvinyl alcohol (PVA) fibres on slant shear tests with different slants of the repair interface, they indicated that the incorporation of PVA fibres in repair materials improves their interface properties by minimizing shrinkage and micro-cracks propagation.^18,19

Self-compacting mortar is considered as an ideal material for reparation and rehabilitation of reinforced concrete (RC) elements. Because of its advantages over the normal mortar on decreasing the construction time and improving the filling ability of reinforced concrete structures.^20,21 Its high flowability and stability are due to the high cement content, thus it is necessary to use inert fillers and supplementary cementitious materials.²²

Several waste materials and by-products have been used in concrete as Supplementary Cementitious Materials (SCMs) and aggregates to enhance some properties of concrete and reduce the problem of their disposal.²³ They can be used either as an addition, a partial replacement for portland cement^24–27 or as aggregate in concrete.^28–30 The recycling of waste materials is a topical issue in order to minimize pollution, protect the environment and provides economic advantages. Numerous researchers have utilized mineral admixtures such as natural pozzolana (NP) in producing repair materials. They found that including NP as a binder gave compatible repair mortars.^31,32 Benyahia et al. substituted 20% of naturel pozzolana and 10% of limestone dust as a replacement of cement. They indicated that the use of NP and limestone dust are suitable materials to produce self-compacting repair material.³³

The marble, as a natural product, is extracted as blocks from quarries then transported to the factory for processing. Through the cutting blocks process, about 50% of it is the total amount of wastes,³⁴ which generates environmental problems^35,36 due to the presence of high volume of calcium oxide.³⁷ Several researchers in recent years have been used marble waste in concrete. Thus, recycling marble scrap powder has multiple positive effects.^38–43

A satisfactory performance could be resulted with the use of 10%–15% of marble powder as a substitution of cement in concrete mixes and consequently reduce the CO₂ emission.⁴⁴ Arel⁴⁵ concluded that a reduction about 12% in the global annual CO₂ emission is recorded by using 5%–10% of marble dust. Marble powder incorporation as cement replacement lead to workability enhancement^46,47 which is related to its shape, its texture of particles surface and its fineness.³⁸ Marble powder can also improve cohesivity and other mechanical properties by using it as filler with a very fine particle size distribution.⁴⁴ Shawki et al.⁴² resulted in a satisfactory rheological properties by using 10% of recycled marble powder in self-compacting concrete which ensure its suitability for the construction application. Utilizing marble powder as a partial replacement of cement up to 20% was found to increase compressive strength^46,48–50 and flexural strength^51–53 probably due to its filling effect. Other study reached that marble powder seems to decrease the mechanical strength⁵⁴ as a result of decreasing the amount of C-S-H gels. Ashish and Verma⁵⁵ reported that the combination of marble powder and fly ash gave a higher packing density and showed better performances that cannot be found by using them separately. Many research investigated the use of waste marble powder as cement and sand substitution on the properties of paste, mortar and concrete. However, limited researches have been done to experiment its feasibility on the durability of repair systems (repair mortar/old concrete).

About 50% of the repairs carried out on concrete structures end with a premature failure, as a consequence to the debonding of the repair layer due to a poor adhesion on the damaged concrete surface. The durability of the reparation depends on⁵⁶: External exposure environment, characteristics of the substrate, characteristics of the used materials and maintenance. To guaranty the durability of concrete reparation, the comprehension of the cementitious behaviour of repair materials is very important.

View of the issue of huge amount of waste marble powder produced from the process of cutting marble blocks, the valorization of this waste and its use as partial replacement of cement seems to be the ideal technique to its disposal in nature. Besides to its contribution in the reduction of cement consumption and CO₂ emission during its production. According to the few previous researches have been conducted on the impact of the combination of polypropylene fibres and marble powder on adhesion strength of repair materials on the substrate concrete and the durability of the repair system, the present paper is developed. First, the optimization of fibre’s dosage was assessed on rheological and mechanical properties. Then, the combined effect of polypropylene fibre and the substitution of cement by marble powder was evaluated on SCRMs prepared with 0%, 10%, 15%, 25% and 30% of MP and 0.06% of polypropylene fibre. SCRMs were tested for fresh properties, mechanical characteristics, elasticity modulus, sorptivity coefficient and adhesion strength.

Experimental

Materials

In this study, cement (C) class 52.5 N with a fineness of 3300 m²/kg and specific gravity of 3030 kg/m³ was used. Marble powder (MP) was crushed for 2 h to prepare a powder with higher fineness equals to 5000 m²/kg with a mean-particle diameter of 80 μm, a specific gravity of 2620 kg/m³ and bulk density of 1046 kg/m³. Table 1 gives the chemical component of cement and MP, Figures 1 and 2 illustrate laser particle size distribution and XRD analysis of both powders. Table 2 shows the characteristics of polypropylene fibre (PPF). The used river sand is a class 0/5, with a specific density of 2620 kg/m³ and fineness modulus of 2.41. Polycarboxylate superplasticizer (Sp) was used.

Table 1.

Chemical analysis of cement and marble powder.

Compound	Cement (%)	Marble powder (%)
CaO	67.60	53.42
SiO₂	14.87	–
Al₂O₃	5.60	2.92
K₂O	0.74	–
Fe₂O₃	3.32	0.01
SO₃	3.31	–
Cl	0.03	–
P₂O₅	–	0.02
CO₂	3.70	43.60

Figure 1.

Size distribution by laser of cement and marble powder.

Figure 2.

XRD analysis of cement and marble powder.

Table 2.

Polypropylene fibre characteristics.

Table 1 shows that the main component of cement and MP is calcium oxide (CaO), with a proportion of 67.60% and 53.42%, respectively. Compared to the cement, MP has a lower amount of aluminium oxide (Al₂O₃) and iron oxide (Fe₂O₃). To analyse the microstructure of cement, marble powder and polypropylene fibre microscopies images (MEB) are presented in Figure 3. Figure 3(a) and (b) give the morphology, particle size and shape of the C and MP. Both materials have irregular, angular particle structure and a rough texture. Similar result was found by Singh et al.⁵⁷ Polypropylene fibre is showed in Figure 3(c). It has a smooth surface and a circular cross section.

Figure 3.

Microscopic images (MEB) of: (a) cement, (b) marble powder, and (c) polypropylene fibre.

Methods

Two series of mixtures were prepared and presented in Table 3. Series 1 contains five mixtures with different dosages of polypropylene fibre 0%, 0.03%, 0.06%, 0.09%, 0.12% relative to the total volume. Six mixtures belong to series 2 which contains one dosage of fibre and six different dosages of marble powder. The choice of 10%, 15%, 20%, 25% and 30% of MP and 0.06% of fibre reveals to the optimal dosage with a good compressive and flexural strength at 28 days. Fibre’s dosage and W/B ratio were kept constant in all mixtures. All mixes were prepared according to the requirements of the European Federation for Specialist Construction Chemicals and Concrete Systems EFNARC 2005.⁵⁸

Table 3.

Composition of mixtures (kg/m³).

Series	Mixtures	Cement (kg)	Marble powder (kg)	Sand (kg)	Fibre (%)	W/B	Sp (%)	Slump flow (cm)
Series 1	FM0	872.51	00	1170	0.00	0.3	0.6	25
	FM3	872.51	00	1170	0.03	0.3	0.5	27
	FM6	872.51	00	1170	0.06	0.3	0.6	26
	FM9	872.51	00	1170	0.09	0.3	0.6	26
	FM12	872.51	00	1170	0.12	0.3	0.6	27
Series 2	SCRM0	872.51	00	1170	0.06	0.3	0.6	25
	SCRM10	785.26	87.25	1170	0.06	0.3	0.6	27
	SCRM15	741.64	130.88	1170	0.06	0.3	0.6	27
	SCRM20	698.01	174.50	1170	0.06	0.3	0.5	27
	SCRM25	654.39	218.13	1170	0.06	0.3	0.4	26
	SCRM30	620.76	261.75	1170	0.06	0.3	0.4	25.5

Fresh mortars were characterized by slump flow test using mini cone in truncated shape (height of 60 mm, upper and lower diameter of 70 and 100 mm). Bleeding, segregation and fibre’s agglomeration were also visually checked. The diameter value was measured in both directions and their average is defined as slump-flow diameter. Prismatic moulds (40 × 40 × 160 mm³) were filed with fresh mortar and covered with a plastic film then demoulded after 24 h. Mechanical properties were assessed (flexural and compressive strength) at 3, 7, 28 and 90 days according to standard EN 12190-6,⁵⁹ after conservation in saturated-lime water (T = 20°C ± 2°C, RH = 100%). Flexural strength is the average of three specimens, while the compressive strength is the average of the six resulting halves from the flexural strength test. In addition, modulus of elasticity (E_D) was carried out on (60 × 90) mm³ cylindrical specimens using the ultrasonic pulse velocity test (UPVT; Figure 4(a)) after 28 and 90 days of curing in the laboratory (T = 20°C ± 5°C, RH = 30% ± 5%), according to EN 12504-4.⁶⁰ The E_D is calculated with this equation:

E_{D} = ρ v^{2}

(1)

where:

E_D: Dynamic modulus of elasticity (MPa)

ρ: Density of dry specimen (kg/m³)

$v$ : Ultrasonic velocity (km/s)

Figure 4.

(a) Ultrasonic pulse velocity test, (b) sorptivity and (c) adhesion strength test.

The sorptivity coefficient ( $S$ ) was measured after 28 days of curing in saturated-lime water according to the European standard EN 1015-18.⁶¹ The SCRM prism specimens (40 × 40 × 160 mm³) were dried in oven at 60°C for at least 48 h until mass stabilization. The lateral sides of the prisms were covered using a resin epoxy. Then they were placed vertically over a grid in water with 5 mm of depth (Figure 4(b)). The coefficient of sorptivity ( $S$ ) is the slope of each curve between 0 and 2 h measured according to the following expression:

\frac{Q}{A} = S . \sqrt{t}

(2)

Where $Q$ is the amount of water absorbed (kg), $A$ is the surface area in contact of water (m²), $t$ is the time (h), $S$ is the sorptivity coefficient (kg/m².h^1/2).

Adhesion test was evaluated using bonding tensile method (Figure 4(c)) on prismatic specimens (40 × 40 × 160 mm³; half SCRM/half substrate mortar). The substrate mortar (SM) was prepared and cured in humid chamber (T = 20°C ± 5°C, RH = 80% ± 5%) for 28 days before the application of SCRM. For a good adhesion, the substrate mortar was scratched and humidified before casting the SCRM. These composite specimens were tested after 7, 28, and 90 days of air curing. The mechanical characteristics of substrate mortar used in this study are set out in Table 4.

Table 4.

Flexural and compressive strength of the substrate mortar (SM).

Age (days)	7	28
Flexural strength (MPa)	6.5	7.1
Compressive strength (MPa)	32	40

Results and discussion

Optimization of fibre dosage

Fresh properties

Table 3 gives the slump flow of all mortars. It can be seen from the slump flow diameter that all mixtures are in the target of 25 ± 2 cm. Sp dosage was adjusted to obtain the slump flow required by EFNARC 2005.⁵⁸ The results reveal that by adding PPF into the mortar, its slump flow diameter increases slightly in all mixes but still in the target required by EFNARC 2005. That could be due to the smooth surface and hydrophobic nature of PPF so that it does not absorb water. In addition to the flexible character and small cross section of the used fibre about 32 µm, as shown in Figure 3(c), which contribute in minimizing the friction between the sand grains by increasing the distance between them thus allows the flowing of the self-compacting mortar. It was observed by Karthik and Maruthachalam⁶² that hybridization of PPF and steel fibres gave a high workability performance of fresh concrete. In contrast to other findings, slump flow was found to decrease with the addition of PPF.^14,15 The use of 0.03% and 0.06% of fibre showed a good dispersion and distribution in the matrix and presented the best rheological properties, while 0.09% and 0.12% presented an agglomeration of fibres (Figure 5).

Figure 5.

Agglomeration in mortars with 0.09% and 0.12% of fibre dosage.

Mechanical properties

After determining workability properties, mechanical strength was evaluated. Figure 6 provides the variation of compressive and flexural strength in function of fibre dosage at 28 days.

Figure 6.

Evolution of mechanical strength in function of fibre dosage at 28 days.

The results show that the addition of polypropylene fibre in the matrix enhances both flexural and compressive strengths of fibre’s mortar. It is clearly seen that mortar containing 0.06% of fibre has developed the highest compressive strength value of 97.7 MPa at 28 days with an increment about 6.7% compared to control mortar. That could be related to the good dispersion of fibres through the mix (as noted in workability behaviour) which led to the ideal granular skeleton. This confirms also the effectiveness of PPF in delaying micro-cracks improvement and reducing their propagation. While mortar with 0.12% PPF exhibited the most important flexural strength with an improvement of 24.7% compared to control mortar. This could be due to the good length of the used fibres and its bridging effect where the tensile stress was transferred to the fibre.

Visual observation demonstrates that mortars with 0% and 0.03% of fibre failed suddenly once the mortar was cracked however, mortars with 0.06%, 0.09% and 0.12% did not fully separate. This could be related to the good adhesion between the fibre and the paste. In line with these results, several researchers have concluded that PPF incorporation enhances the mechanical performance. Sayed Mohammad Akid et al.⁶³ used polypropylene fibre and fly ash, they found a gain in compressive and tensile strength at 28 days where polypropylene fibre restrained and reduced the growth of initial and macro cracks. Zhou et al.⁶⁴ showed that the incorporation of PPF gave high enhancing coefficients in fibre reinforced concrete. Çelik and Bingöl⁶⁵ reported that the use of fibres delayed the fracture of the concrete by restricting the lateral expansion in compressive test, also PPF showed a ductile post peak behaviour in flexural test. Belaidi et al.¹² mentioned that the use of both silica fume and synthetic fibres enhanced the mechanical properties. We conclude that mortar with 0.06% of fibre is the optimal dosage which reveals to the good compressive and flexural strength at 28 days, also gave the best dispersion and the most homogenous mix in fresh state.

Optimization of marble powder dosage

Fresh properties of SCRMs

Figure 7 illustrates slump flow and superplasticizer demand of self-compacting repair mortars (SCRMs) contains 0.06% of PPF in function of the increase in marble powder percentage.

Figure 7.

Slump flow and superplasticizer demand of SCRMs in function of MP dosage.

The obtained results showed that increasing MP content from 0% to 15% leads to increase slightly slump flow from 25 to 27 cm, respectively, with superplasticizer (Sp) dosage equal to 0.6%. Then the dosage of Sp was adjusted in mortars incorporating MP beyond 15% to obtain slump flow required by EFNARC.⁵⁸ That could be attributed to the filling and dilution effect of MP which increases the mobility of the cement particles. Moreover, at an early phase of hydration, the inert nature of MP, releases a part of the mixing water which causes lubrication of the grains, and improves the mixture’s workability.³⁹ Other researchers recorded that limestone fillers fill the inter-particle voids of the mortar and increase the compactness Φ * paste of the mixture which leads to release the water trapped in the voids and improving the workability.⁶⁶ The visual observations showed no bleeding or segregation phenomenon. Similar results were reported by Ruiz-Sánchez et al.⁴⁶ and Rashwan et al.,⁴⁷ they replaced cement by MP and resulted in workability enhancement.

Mechanical strength of SCRMs

Compressive and flexural strength of SCRMs reinforced with 0.06% of polypropylene fibre in function of MP substitution at 3, 7, 28 and 90 days are given in Figures 8 and 9, respectively.

Figure 8.

Variation of the compressive strength in function of marble powder of SCRMs at 3, 7, 28 and 90 days.

Figure 9.

Variation of the flexural strength in function of marble powder of SCRMs at 3, 7, 28 and 90 days.

It is observed that mechanical properties increase with the proceeding in curing times from 3 to 90 days, while, they decrease with increasing the substitution levels of marble powder. The gain rate in compressive strength from 3 days to 7, 28 and 90 days of conventional mortar is higher than that of mortars with MP.

At an early age (3 days), the compressive strength generates a comparative value in all mortars compared to control mortar. That may be attributed to micro filler effect of MP which fill the voids and lead to denser paste.⁶⁷ Also the transition zone and cement paste is improved by filler effect.⁵⁷ At 7 days, 10% of MP content gives an augmentation in compressive strength about 8% compared to control mortar, while a reduction was observed with the increase of MP beyond 15%. A slight and insignificant diminution was generated in all self-compacting repair mortars at 28 days compared to control mortar. At later age (90 days), the strength started to decrease at higher level from 20% of replacement. This diminution in the strength gain is possibly due to the reduction in hydration products C₃S and C₂S.^68–71

Singh et al.⁵⁷ and Kore et al.⁴⁴ observed that for 10% and 15% replacement level, the compressive strength increases then starts decreasing for 20% and 25% of replacement at 28 days of curing. Aliabdo et al. and other researchers^68–71 noted that compressive strength is enhanced with 10% replacement level of cement by MP.⁷² Since that lime-stone fine has similar mineralogical composition to marble powder, Voglis et al.⁷³ and Guemmadi et al.⁷⁴ indicated that lime-stone fine reacts with the alumina pastes of cement to form a calcium non-carbo aluminate hydrate phase which result in significant enhancement in strength, despite that lime-stone fine does not have a pozzolanic reaction. Singh et al. recorded that many factors can influence the reactivity of marble powder such as its fineness. In order to obtain a compressive strength close to that of control concrete, using the entire sample passing through 300 µm sieve could be beneficial.⁵⁷ We note that all repair mortars exhibited a compressive strength higher than 45 MPa at 28 days, fulfilling the requirements of class R4 materials according to the EN 1504-3 Standards.⁷⁵

Concerning the results of flexural strength, its trend was similar to that of compressive strength. An increase is observed in function of age, and a decrease in strength after adding MP. At 3 days, SCRM10 showed an enhancement about 16.3% compared to control mortar, while SCRM15, SCRM20 and SCRM25 gave a comparable value. A diminution about 12.2% was generated in SCRM30. At 7 days, SCRM10 gave the same strength as that of SCRM0, while a reduction was observed in the other mixtures. A decrease in strength is observed at 28 days, except for SCRM15 exhibited the same strength value with SCRM0. At longer age (90 days), the use of MP leads to a diminution in flexural strength, it is well observed from 15% of MP. This decrease is a consequence to the reduction in C₃S and C₂S required for hydration process and responsible for strength development.^69,70,76,77 Agarwal and Gulati⁷⁸ reported that 10% and 20% of substitutions by MP resulted in disadvantages in performance of 12% and 25%, respectively, after 180 days of curing.

The correlation between compressive and flexural strengths are outlined by various researchers and can be summarized in a different way:

f_{r} = k f_{c}^{α}

(3)

Where $f_{c}$ represents compressive strength in MPa and $f_{r}$ is flexural strength in MPa. Correlation between compressive and flexural strength findings proposed in the study, represented by equation (4), it was used to model the correlation among compressive and flexural strength for SCRMs mixtures. Coefficients k and α were obtained through nonlinear regression analysis using the test results, which were considered as the main variables. The values obtained were k and α by nonlinear regression analysis using test results, which were considered as the main variables, are 0.048 and 1.2, respectively. The corresponding strong correlation coefficient $R^{2}$ = 0.83 can be expressed as follows:

f = 0.048 . f_{c}^{1.2}

(4)

The previous expression can be effectively utilized to estimate and predict compressive strength using the findings obtained from the flexural strength test as illustrated in Figure 10.

Figure 10.

Correlation between flexural and compressive strengths of SCRMs.

Modulus of elasticity of SCRMs

The variation of elasticity modulus at 28 and 90 days is presented in Figure 11. There is a clear trend of decreasing in modulus of elasticity (E_D) with the increment in marble powder replacement. The results demonstrate that modulus of elasticity follows the same trend of the compressive strength, where the MP effects negatively the E_D value. The highest modulus values are recorded to SCRM0 at both ages thanks to the high content of cement. The diminution in E_D could be due to the decrease in the volume of hydration products compared to control mortar and to the evaporation of water necessary for the hydration in case of air-cured conditions.

Figure 11.

Effect of marble powder percentage on the modulus of elasticity at 28 and 90 days.

On the other hand, the elastic modulus of all self-consolidating repair mortar (SCRM) mixtures exhibited an increase over time, particularly noticeable after 90 days of curing. For example, during the extension of the curing period from 28 to 90 days, the elastic modulus of all the SCRMs increase between 8.7% and 13.2%.

All E_D values were higher than the lower limit (20 GPa) required by the EN 1504-3 Standards for Class R4 repair mortars. It could be due to the high fineness of the used MP that gave a denser and less porous specimen, which enhance the compactness of the mix, fill the voids and denser paste is obtained. Because of theirs high ductility, composite materials are effective and good repair materials as it was reported by several researcher.^79–81 Uysal and Yilmaz⁸² indicated that modulus of elasticity decreases with increasing the replacement rates of mineral admixtures. Other researchers found that using both PPF and recycled aggregates lead to a decline in E_D.

Various models and correlations have been suggested in the literature to estimate the modulus of elasticity of concrete, predominantly based on the concrete’s compressive strength. This study has formulated an empirical correlation between the modulus of elasticity and compressive strength, which can be articulated as:

E_{D} = 0.86 f_{c}^{0.8}

(5)

Here, $f_{c}$ is the compressive strength in MPa and $E_{D}$ is the elastic modulus in GPa.

Equation (5) demonstrates a strong correlation between elastic modulus and compressive strength, as evidenced by a coefficient of determination (R²) exceeding 0.86. Figure 12 further shows a remarkable correlation between the compressive strength and the modulus of elasticity.

Figure 12.

Correlation between the dynamic modulus of elasticity and the compressive strengths of SCRMs.

Sorptivity

Sorptivity coefficient (S) at the age of 28 days is illustrated in Figure 13. The coefficient S varies between 0.26 and 0.53 kg/m².h^1/2. It is often measured to predict the durability of the material.⁸³

Figure 13.

Variation of sorptivity of SCRMs at 28 days.

It can be clearly seen from Figure 13 that the use of high volume of marble powder contents increases significantly the coefficient of sorptivity at 28 days of water-cured conditions. SCRM0 presented the lowest sorptivity compared to all repair mortars, while SCRM20 gives the highest coefficient. A comparable value was observed with 10% and 30% of MP with 39% of evolving compared to SCRM0. Mortars SCRM15, SCRM20 and SCRM25 showed more than 45% of increment. This could be explained by the decrease in the volume of hydration products compared to control mortar and the inert nature of marble powder. Many researchers reported that sorptivity is directly related to formation of C-S-H gel, C-H crystalline and filling the pores.^84,85 Other study⁸⁶ concluded that the use of marble waste particles finer than 150 microns to replace cement in ranges of 5%, 10%, 15% and 20% reduced water absorption by more than 40%.

Another study investigated the use of MP and found that the water absorption decreases gradually when increasing MP up to 20%.⁶⁹ Ghrici et al.³³ found that the substitution of 10% of limestone dust gave a capillary absorption coefficient about 0.48 kg/m².h^1/2. Choucha et al.⁸⁷ used naturel pozzolana (NP) as a cement replacement with a fineness about 4100 cm²/g and reported that a high volume of NP content increases significantly the capillary absorption at 28 days. Sayed Mohammad Akid et al. studied sorptivity of concrete containing 0%, 0.06%, 0.12% and 0.18% of polypropylene fibres and 15% of fly ash. They concluded that the samples with 0.06% PPF and 15% fly ash as well as 0.12% PPF and 15% fly ash exhibited the lowest sorptivity coefficient compared to control concrete.⁶³ As a conclusion, all the repair mortars meet the requirement for class R4 (˂0.5 kg/m².h^0.5) according to the EN 1504-3 except SCRM20.

A good correlation exists between sorptivity and dynamic modulus of elasticity with a coefficient of correlation R²= 0.73. The correlation can be presented as follows in equation (6) and Figure 14:

E_{D} = - 0 {. 0174 S}^{2} + 1.0131 S - 14.263

(6)

Where, E_D is dynamic modulus of elasticity (GPa) and S is the sorptivity (kg/m².h^0.5).

Figure 14.

Correlation between sorptivity and the dynamic modulus of elasticity at 28 days.

Adhesion strength

The adhesion strength between repair mortar (SCRM) and substrate mortar (SM) was evaluated by flexural bond test in function of marble powder substitution at 7, 28, and 90 days of curing (Figure 4(c)). A first analysis of Figure 15 shows that flexural bond strength enhanced with age. At an early age (7 days), the enhancement is at high level more than 25% compared to mortar with 0% of MP. This is in line with the study conducted by Vardhan et al.⁸⁸ on the effect of waste marble powder as cement replacement and revealed positive effect on early age compressive strength (7 days). At 28 days, the gain in bond strength of SCRM10, SCRM15 and SCRM20 was in the order of 20%, 20% and 8%, respectively. In the long term (90 days), only SCRM10 and SCRM15 showed an increase in bond strength about 18%–20%. Comparable values are obtained in SCRM0 and SCRM20. Repair mortars with 25% and 30% MP are characterized with lower bond strength compared to SCRM0 at 28 and 90 days. The improvement in the adhesion could be explained by the enhancement at the interface between the repair material and the old mortar caused by the increase in the friction between them; due to the angularity shape of the MP (Figure 3(b)). Similar results were obtained by Benyahia³³ and Aliabdo and Abd_Elmoaty.⁸⁹ Moreover, the fine particles size of marble powder contributes in filling microvoids, thus resulted in denser microstructure. As a consequence, it reduces the porosity and improves the bond strength by enhancing the interface contact.

Figure 15.

Variation of adhesion strength in function of marble powder percentage at 7, 28 and 90 days.

The obtained bonding results showed that the composite samples exhibited the same failure mode at all ages. Interface damage occurred in all test cases; the SCRM are completely separated from the substrate. Amar et al.⁹⁰ investigated the adhesion strength using waste glass powder (WGP) at 28 and 56 days. They concluded that using 10% of WGP as cement replacement had good adhesion with the substrate mortar, all the damage occurred in the SM at both ages.

Based on the results presented in Figure 15, it can be concluded that using 10%, 15% and 20% of MP are considered as suitable materials for use as cement replacement to produce self-compacting repair mortars.

Conclusion

Based on the experimental work carried out on self-compacting repair mortar (SCRM) reinforced with polypropylene fibre and marble powder at different dosages (0%, 10%, 15%, 20%, 25% and 30%). SCRMs were tested on fresh state, compressive strength, flexural strength, modulus of elasticity, sorptivity and adhesion strength. The following conclusions can be made:

The optimal percentage of fibre is recorded to 0.06% which yield to a good distribution in the matrix, a maximum compressive strength and good flexural behaviour.

The use of both polypropylene fibres and marble powder is beneficial for workability enhancement which is due to the hydrophobic surface of PPF and inert nature of MP.

According to the mechanical performance, marble powder can be used as cement replacement with PPF in repair mortars up to 30%. All SCRMs found to fulfil the requirements of class R4.

Modulus of elasticity changed in a very low range, its results reveal that 10% and 15% of MP showed insignificant decrease in the E_D. From 20% an important diminution is obtained. Besides, a very good relationship is obtained between compressive strength and flexural strength, between elasticity modulus and compressive strength and between elasticity modulus and sorptivity coefficient.

Adding marble powder to the mix augment significantly the sorptivity coefficient. However, all self-compacting repair mortars satisfy the EFNARC specification, except SCRM20.

The adhesion test showed that using up to 20% of MP in repair mortars enhance bonding strength due to the fine particle size of MP and its contribution in filling the microvoids, enhancing the compactness of the mixture and thus enhancing the interface contact between repair mortars and the old mortar.

The synergistic work of MP and PPF revealed in appreciable results in mechanical performance and adhesion strength that cannot be achieved if they were used separately.

In general, the present work investigated the utilization of the marble powder in self-compacting repair mortar reinforced with PPF fibre in accordance with the international standard specifications and satisfactory results were obtained at replacement ratio of up to 30% MP with 0.06% of PPF.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Fatiha Bendjilali

Mohamed Said Mansour

References

Goulart

SAS

Oliveira

Teixeira

, et al. Mechanical behaviour of polypropylene reinforced palm fibers composites. Procedia Eng 2011; 10: 2034–2039.

Nguyen

Dao

VTN

Lura

Tensile properties of concrete at very early ages. Constr Build Mater 2017; 134: 563–573.

Hussain

Bhunia

Singh

, et al. Mechanical strength and durability of mineral admixture concrete subjected to accelerated carbonation. J Struct Integrity Maint 2018; 3(1): 44–51.

Hung

C-C

Y-F

Y-M.

Mechanical properties and self-healing evaluation of strain-hardening cementitious composites with high volumes of hybrid pozzolan materials. Compos B Eng 2018; 133: 15–25.

ACI Committee. Guide to durable concrete. Farmington Hills, MI: American Concrete Institute, 2016.

Hadjoudja

Benzaid

Mesbah

H-A

, et al. Effect of mineral additions and metal fibers on the resistance of cracking of the dune sand concretes. Iran J Sci Technol Trans Civil Eng 2021; 45(3): 1523–1537.

Irki

Debieb

Kadri

E-H

, et al. Effect of the length and the volume fraction of wavy steel fibers on the behavior of self-compacting concrete. J Adhes Sci Technol 2017; 31(7): 735–748.

Bendjillali

Bendjilali

Krobba

Evaluating shrinkage and mechanical performances of polypropylene hybrid fibers reinforced mortar. Adv Mater Res 2022; 11(1): 211–224.

Sivakumar

Kavitha

Prince Arulraj

, et al. An experimental study on combined effects of glass fiber and Metakaolin on the rheological, mechanical, and durability properties of self-compacting concrete. Appl Clay Sci 2017; 147: 123–127.

10.

Naraganti

Pannem

RMR

Putta

Impact resistance of hybrid fibre reinforced concrete containing sisal fibres. Ain Shams Eng J 2019; 10(2): 297–305.

11.

Felekoğlu

Türkel

Altuntaş

Effects of steel fiber reinforcement on surface wear resistance of self-compacting repair mortars. Cem Concr Compos 2007; 29(5): 391–396.

12.

Belaidi

ASE

Benabed

Soualhi

Physical and mechanical properties of concrete repair materials in dry and hot-dry environment. J Adhes Sci Technol 2015; 29(6): 543–554.

13.

Hassan

ElNemr

Goebel

, et al. Effect of hybrid polypropylene fibers on mechanical and shrinkage behavior of alkali-activated slag concrete. Constr Build Mater 2024; 411: 134485.

14.

Zhang

QF.

Effect of polypropylene fiber on durability of concrete composite containing fly ash and silica fume. Compos B Eng 2013; 45(1): 1587–1594.

15.

Tabatabaeian

Khaloo

Joshaghani

, et al. Experimental investigation on effects of hybrid fibers on rheological, mechanical, and durability properties of high-strength SCC. Constr Build Mater 2017; 147: 497–509.

16.

Bhutta

Farooq

Zanotti

, et al. Pull-out behavior of different fibers in geopolymer mortars: effects of alkaline solution concentration and curing. Mater Struct 2016; 50(1): 80.

17.

Bhutta

Borges

PHR

Zanotti

, et al. Flexural behavior of geopolymer composites reinforced with steel and polypropylene macro fibers. Cem Concr Compos 2017; 80: 31–40.

18.

Yoo

D-Y

Banthia

Mechanical properties of ultra-high-performance fiber-reinforced concrete: a review. Cem Concr Compos 2016; 73: 267–280.

19.

Kanda

VC.

Interface property and apparent strength of high-strength hydrophilic fiber in cement matrix. J Mater Civ Eng 1998; 10(1): 5–13.

20.

Turk

Viscosity and hardened properties of self-compacting mortars with binary and ternary cementitious blends of fly ash and silica fume. Constr Build Mater 2012; 37: 326–334.

21.

Ashish

Verma

SK.

Determination of optimum mixture design method for self-compacting concrete: validation of method with experimental results. Constr Build Mater 2019; 217: 664–678.

22.

Benabed

Kadri

E-H

Azzouz

, et al. Properties of self-compacting mortar made with various types of sand. Cem Concr Compos 2012; 34(10): 1167–1173.

23.

Negm

El Nemr

Elgabbas

, et al. High and normal strength concrete using grounded vitrified clay pipe (GVCP). Clean Mater 2022; 5: 100107.

24.

Chen

, et al. Adding granite polishing waste as sand replacement to improve packing density, rheology, strength and impermeability of mortar. Powder Technol 2020; 364: 404–415.

25.

Yingliang

Jingping

Zhengyu

, et al. Effect of superfine blast furnace slags on the binary cement containing high-volume fly ash. Powder Technol 2020; 375: 539–548.

26.

Zhuo

Zhu

, et al. Adding ceramic polishing waste as paste substitute to improve sulphate and shrinkage resistances of mortar. Powder Technol 2020; 362: 149–156.

27.

ElNEMR

Shaltout

. Rheological and mechanical characterization of self-compacting concrete using recycled aggregate. IOP Conf Ser Earth Environ Sci 2024; 49(1). DOI: 10.20944/preprints202404.1815.v1.

28.

Adhikary

Ashish

Sharma

, et al. Lightweight self-compacting concrete: a review. Resour Conserv Recycl 2022; 15: 200107.

29.

Ashish

Verma

SK.

Robustness of self-compacting concrete containing waste foundry sand and metakaolin: a sustainable approach. J Hazard Mater 2021; 401: 123329.

30.

Ashish

Verma

, et al. High volume waste foundry sand self-compacting concrete – transitioning industrial symbiosis. Process Saf Environ Prot 2023; 173: 666–692.

31.

Veiga

Velosa

Magalhães

Experimental applications of mortars with pozzolanic additions: characterization and performance evaluation. Constr Build Mater 2009; 23(1): 318–327.

32.

Pavlidou

Systematic analysis of natural pozzolans from Greece suitable for repair mortars. J Therm Anal Calorim 2012; 108(2): 671–675.

33.

Ghrici

Choucha

Ghrici

, et al. Influence of limestone dust and natural pozzolan on engineering properties of self-compacting repair mortars. Frat Ed Integrità Strutt 2018; 12(45): 135–146.

34.

Demirel

Alyamaç

. Waste marble powder/dust. In: Waste and supplementary cementitious materials in concrete. Amsterdam: Woodhead Publishing, Elsevier, 2018, pp.181–197.

35.

Ashish

DK.

Concrete made with waste marble powder and supplementary cementitious material for sustainable development. J Clean Prod 2019; 211: 716–729.

36.

Gill

Rathanasalam

Jangra

, et al. Mechanical and microstructural properties of fly ash-based engineered geopolymer mortar incorporating waste marble powder. Energy Ecol Environ 2024; 9(2): 159–174.

37.

Ashish

DK.

Feasibility of waste marble powder in concrete as partial substitution of cement and sand amalgam for sustainable growth. J Build Eng 2018; 15: 236–242.

38.

Siddique

Belarbi

Sustainable concrete made with ashes and dust from different sources. New Delhi: Elsevier, 2022.

39.

Dada

Belaidi

ASE

Soualhi

, et al. Influence of temperature on the rheological behaviour of eco-mortar with binary and ternary cementitious blends of natural pozzolana and marble powder. Powder Technol 2021; 384: 223–235.

40.

Belaidi

ASE

Kenai

Kadri

E-H

, et al. Effects of experimental ternary cements on fresh and hardened properties of self-compacting concretes. J Adhes Sci Technol 2016; 30(3): 247–261.

41.

Soualhi

Kadri

E-H

Ngo

T-T

, et al. Rheology of ordinary and low-impact environmental concretes. J Adhes Sci Technol 2015; 29(20): 2160–2175.

42.

Shawki

Elnemr

Koenke

, et al. Rheological properties of high-performance SCC using recycled marble powder. Innov Infrastruct Solut 2024; 9(5): 176.

43.

Youssef

Tair

Nemr

. The effects of replacing cement by different marble powders in motars. Conference paper; ICCM 2017; October 2017.

44.

Kore

Vyas

Kabeer K.i

. A brief review on sustainable utilisation of marble waste in concrete. Int J Sustain Eng 2020; 13(4): 264–279.

45.

Arel

HŞ

. Recyclability of waste marble in concrete production. J Clean Prod 2016; 131: 179–188.

46.

Ruiz-Sánchez

Sánchez-Polo

Rozalen

Waste marble dust: an interesting residue to produce cement. Constr Build Mater 2019; 224: 99–108.

47.

Rashwan

Al - Basiony

Mashaly

, et al. Behaviour of fresh and hardened concrete incorporating marble and granite sludge as cement replacement. J Build Eng 2020; 32: 101697.

48.

Khodabakhshian

Ghalehnovi

de Brito

, et al. Durability performance of structural concrete containing silica fume and marble industry waste powder. J Clean Prod 2018; 170: 42–60.

49.

Atiyeh

Aydin

Data for bottom ash and marble powder utilization as an alternative binder for sustainable concrete construction. Data Brief 2020; 29: 105160.

50.

Ince

Hamza

Derogar

, et al. Utilisation of waste marble dust for improved durability and cost efficiency of pozzolanic concrete. J Clean Prod 2020; 270: 122213.

51.

Belouadah

Rahmouni

ZEA

Tebbal

Influence of the addition of glass powder and marble powder on the physical and mechanical behavior of composite cement. Procedia Comput Sci 2019; 158: 366–375.

52.

Prošek

Nežerka

Tesárek

Enhancing cementitious pastes with waste marble sludge. Constr Build Mater 2020; 255: 119372.

53.

Varadharajan

Determination of mechanical properties and environmental impact due to inclusion of flyash and marble waste powder in concrete. Structures 2020; 25: 613–630.

54.

Rana

Kalla

Csetenyi

LJ.

Sustainable use of marble slurry in concrete. J Clean Prod 2015; 94: 304–311.

55.

Ashish

Verma

SK.

An overview on mixture design of self-compacting concrete. Struct Concr 2019; 20(1): 371–395.

56.

Maurenbrecher

RILEM TC 203-RHM: repair mortars for historic masonry: requirements for repointing mortars for historic masonry. Mater Struct 2012; 45(9): 1303–1309.

57.

Singh

Srivastava

Bhunia

An investigation on effect of partial replacement of cement by waste marble slurry. Constr Build Mater 2017; 134: 471–488.

58.

EFNARC. The European Guidelines for Self-Compacting Concrete: Specification, Production and Use. European Federation for Specialist Construction Chemicals and Concrete Systems.

59.

EN 12190-6. Products and systems for the protection and repair of concrete structures-test methods determination of compressive strength of repair mortar.

60.

EN 12504-4. Testing concrete-part 4: determination of ultrasonic pulse velocity, requirements, quality control and evaluation of conformity, structural and non-structural repair due to capillary action of hardened mortar.

61.

EN 1015-18. Methods of test for mortar for masonry, determination of water absorption coefficient. 2002.

62.

Karthik

Maruthachalam

Experimental study on shear behaviour of hybrid fibre reinforced concrete beams. KSCE J Civil Eng 2015; 19(1): 259–264.

63.

Sayed Mohammad Akid

Hossain

Imtiaz Uddin Munshi

, et al. Assessing the influence of fly ash and polypropylene fiber on fresh, mechanical and durability properties of concrete. J King Saud Univ - Eng Sci 2021; 35(7): 474–484.

64.

Zhou

Xiao

, et al. Dispersion, workability and mechanical properties of different steel-microfiber-reinforced concretes with low fiber content. Sustainability 2018; 10(7): 2335.

65.

Çelik

Bingöl

AF.

Effect of basalt, polypropylene and macro-synthetic fibres on workability and mechanical properties of self-compacting concrete. Challenge J Struct Mech 2019; 5(2): 35.

66.

Yahia

Tanimura

Shimoyama

Rheological properties of highly flowable mortar containing limestone filler-effect of powder content and W/C ratio. Cem Concr Res 2005; 35(3): 532–539.

67.

Gencel

Ozel

Koksal

, et al. Properties of concrete paving blocks made with waste marble. J Clean Prod 2012; 21(1): 62–70.

68.

Ulubeyli

Artir

Properties of hardened concrete produced by waste marble powder. Procedia Soc Behav Sci 2015; 195: 2181–2190.

69.

Mashaly

El-Kaliouby

Shalaby

, et al. Effects of marble sludge incorporation on the properties of cement composites and concrete paving blocks. J Clean Prod 2016; 112: 731–741.

70.

Toubal Seghir

Mellas

Sadowski , et al. Effects of marble powder on the properties of the air-cured blended cement paste. J Clean Prod 2018; 183: 858–868.

71.

Anandaraj

Rooby

Awoyera

, et al. Structural distress in glass fibre-reinforced concrete under loading and exposure to aggressive environments. Constr Build Mater 2019; 197: 862–870.

72.

Aliabdo

Abd Elmoaty

AEM

Auda

EM.

Re-use of waste marble dust in the production of cement and concrete. Constr Build Mater 2014; 50: 28–41.

73.

Voglis

Kakali

Chaniotakis

, et al. Portland-limestone cements. Their properties and hydration compared to those of other composite cements. Cem Concr Compos 2005; 27(2): 191–196.

74.

Guemmadi

Resheidat

Chabil

, et al. Modeling the influence of limestone filler on concrete: a novel approach for strength and cost. Jordan J Civ Eng 2009; 3(2): 158–171.

75.

EN 1504-3. Products and systems for the protection and repair of concrete structures- definitions, requirements, quality control and evaluation of conformity-part 3: structural and non-structural repair.

76.

Meddah

Lmbachiya

Dhir

RK.

Potential use of binary and composite limestone cements in concrete production. Constr Build Mater 2014; 58: 193–205.

77.

Toubal Seghir

Mellas

Sadowski

, et al. The effect of curing conditions on the properties of cement-based composites blended with waste marble dust. JOM 2019; 71(3): 1002–1015.

78.

Agarwal

Gulati

Utilization of industrial wastes and unprocessed micro-fillers for making cost effective mortars. Constr Build Mater 2006; 20(10): 999–1004.

79.

Lim

VC.

Durable repair of aged infrastructures using trapping mechanism of engineered cementitious composites. Cem Concr Compos 1997; 19(4): 373–385.

80.

Wang

VC.

High-early-strength engineered cementitious composites. ACI Mater J 2006; 103(2): 9.

81.

Horii

Kabele

, et al. Repair and retro®t with engineered cementitious composites. Eng Fract Mech 2000; 65(2–3): 317–334.

82.

Uysal

Yilmaz

Effect of mineral admixtures on properties of self-compacting concrete. Cem Concr Compos 2011; 33(7): 771–776.

83.

Ban

Zhi

Fei

, et al. Preparation and performance of cement mortar reinforced by modified bamboo fibers. Polymers 2020; 12(11): 2650.

84.

Abdelaziz

Guessasma

Bouaziz

, et al. Date palm spikelet in mortar: testing and modelling to reveal the mechanical performance. Constr Build Mater 2016; 124: 228–236.

85.

Kenai

Rezagui

Yahiaoui

, et al. Performance of repair mortar with natural fibers. MRS Adv 2020; 5(25): 1295–1304.

86.

Huang

Tan

, et al. Use of marble dust as paste replacement for recycling waste and improving durability and dimensional stability of mortar. Constr Build Mater 2018; 166: 423–432.

87.

Choucha

Benyahia

Ghrici

, et al. Effect of natural pozzolan content on the properties of engineered cementitious composites as repair material. Front Struct Civil Eng 2018; 12(3): 261–269.

88.

Vardhan

Siddique

Goyal

Influence of marble waste as partial replacement of fine aggregates on strength and drying shrinkage of concrete. Constr Build Mater 2019; 228: 116730.

89.

Aliabdo

Abd_Elmoaty

. Experimental investigation on the properties of polymer modified SCC. Constr Build Mater 2012; 34: 584–592.

90.

Amar

Salhi

Boubekeur

Effects of waste glass powder on properties of self-compacting repair mortars. Int J Eng Res Afr 2022; 62: 43–56.