In this study, seawater, sea sand and recycled coarse aggregate (RCA) are combined to prepare seawater sea sand recycled aggregate concrete (SSRAC) for use in beams. Nine beams are reinforced with glass fiber reinforced polymer (GFRP) bars, while 2 more beams are reinforced with steel bars for comparison. Unlike reinforced concrete (RC) beams that contain steel bars, SSRAC beams reinforced with GFRP bars (GFRP-SSRAC) are less stiff and ductile. For GFRP-SSRAC beams with a certain shell particle content in this study, the use of seawater and sea sand in concrete decreases the cracking load. The ultimate load is smaller overall for GFRP-SSRAC beams than RC beams with the same reinforcement ratio. The predictions of flexural capacities made using the ACI code are all lower than the test results. When the replacement ratio of RCA is 100%, the predictions for RAC/SSRAC beams using the Chinese code are lower than the measured values. Finally, the measured stress‒strain curves of SSRAC and GFRP bars are used to obtain the moment-curvature relationships according to reinforcement-based and concrete-based calculation methods. These calculations and results are discussed in this paper.
ACI440.1R-15 (2015) Guide for the Design and Construction of Structural Concrete Reinforced with Fiber-Reinforced Polymer (FRP) Bars. Farmington Hills, MI: ACI Committee 440.
2.
ASTM D1141-98 (2013) Standard Practice for the Preparation of Substitute Ocean Water. Philadelphia, PA: Annual Book of ASTM.
3.
BendixenMBestJHackneyC, et al. (2019) Time is running out for sand. Nature571(7763): 29–31.
4.
DongZSunYZhuH, et al. (2022) Shear behavior of hybrid seawater sea-sand concrete short beams reinforced with BFRP reinforcements. Engineering Structures252: 113615.
5.
DongZWuGLianJ (2018a) Experimental study on the durability of FRP bars reinforced concrete beams in simulated ocean environment. Science and Engineering of Composite Materials25(6): 1123–1134.
6.
DongZWuGXuY (2017) Bond and flexural behavior of sea sand concrete members reinforced with hybrid steel-composite bars presubjected to wet-dry cycles. Journal of Composites for Construction21: 040160952.
7.
DongZWuGZhaoX, et al. (2018b) Durability test on the flexural performance of seawater sea-sand concrete beams completely reinforced with FRP bars. Construction and Building Materials19: 671–682.
8.
DongZWuGZhaoX, et al. (2020) The durability of seawater sea-sand concrete beams reinforced with metal bars or non-metal bars in the ocean environment. Advances in Structural Engineering23(2): 334–347.
9.
GB 50608-2020 (2020) Technical Standard for Fiber Reinforced Polymer (FRP) in Construction. Beijing, China: China Planning Press.
10.
HanSZhouAOuJ (2021) Relationships between interfacial behavior and flexural performance of hybrid steel-FRP composite bars reinforced seawater sea-sand concrete beams. Composite Structures277: 114672.
11.
HuaYYinSPengZ (2020) Crack development and calculation method for the flexural cracks in BFRP reinforced seawater sea-sand concrete (SWSSC) beams. Construction and Building Materials255: 119328.
12.
HuangYXiaoJQinL, et al. (2021) Mechanical behaviors of GFRP tube confined recycled aggregate concrete with sea sand. Advances in Structural Engineering24(6): 1196–1207.
13.
JGJ55-2011 (2011) Specification for Mix Proportion Design of Screte. Beijing, China: China Architecture and Building Press.
14.
LiPLiWYuT, et al. (2020) Investigation on early-age hydration, mechanical properties and microstructure of seawater sea sand cement mortar. Construction and Building Materials249: 118776.
15.
LiPYangTZengQ, et al. (2021a) Axial stress-strain behavior of carbon FRP-confined seawater sea-sand recycled aggregate concrete square columns with different corner radii. Composite Structures262: 113589.
16.
LiPZhouYYangT, et al. (2021b) Axial compressive behavior of seawater sea-sand recycled aggregate concrete-filled double-skin non-corrosive tubular columns with square cross-section. Thin-Walled Structures167: 108213.
17.
PanDYaseenSAChenK, et al. (2021) Study of the influence of seawater and sea sand on the mechanical and microstructural properties of concrete. Journal of Building Engineering42: 103006.
18.
QuFLiWWangK, et al. (2021) Effects of seawater and undesalted sea sand on the hydration products, mechanical properties and microstructures of cement mortar. Construction and Building Materials310: 125229.
19.
SunJDingZLiX, et al. (2021) Bond behavior between BFRP bar and basalt fiber reinforced seawater sea-sand recycled aggregate concrete. Construction and Building Materials285: 122951.
20.
TengJYuTDaiJ, et al. (2011) FRP Composites in New Construction: Current Status and Opportunities. Hangzhou, Zhejiang: in Proceedings of the 7th national conference on FRP composites in infrastructure.
21.
WangCXiaoJZhangC, et al. (2020) Structural health monitoring and performance analysis of a 12-story recycled aggregate concrete structure. Engineering Structures205: 110102.
22.
WangZXieJLiJ, et al. (2022) Flexural behaviour of seawater–sea sand concrete beams reinforced with GFRP bars: effects of the reinforcement ratio, stirrup ratio, shear span ratio and prestress level. Journal of Building Engineering54: 104566.
23.
XiaoJZhangKZhangQ (2021) Strain rate effect on compressive stress-strain curves of recycled aggregate concrete with seawater and sea sand. Construction and Building Materials300: 124014.
XiaoJQiangCNanniA, et al. (2017) Use of sea-sand and seawater in concrete construction: current status and future opportunities. Construction and Building Materials155: 1101–1111.
26.
XiaoJZhangKAkbarnezhadA (2018) Variability of stress-strain relationship for recycled aggregate concrete under uniaxial compression loading. Journal of Cleaner Production181: 753–771.
27.
XiaoJZhangQZhangP, et al. (2019) Mechanical behavior of concrete using seawater and sea-sand with recycled coarse aggregates. Structural Concrete20(5): 1631–1643.
28.
XiongZWeiWHeS, et al. (2021) Dynamic bond behaviour of fibre-wrapped basalt fibre-reinforced polymer bars embedded in sea sand and recycled aggregate concrete under high-strain rate pull-out tests. Construction and Building Materials276: 122195.
29.
YangSLiLSunZ, et al. (2021) A closed-form fracture model to predict tensile strength and fracture toughness of alkali-activated slag and fly ash blended concrete made by sea sand and recycled coarse aggregate. Construction and Building Materials300: 123976.
30.
YounisAEbeadUSuraneniP, et al. (2020) Short-term flexural performance of seawater-mixed recycled-aggregate GFRP-reinforced concrete beams. Composite Structures236: 111860.
31.
ZhangKXiaoJHouY, et al. (2022a) Experimental study on carbonation behavior of seawater sea-sand recycled aggregate concrete. Advances in Structural Engineering25(5): 927–938.
32.
ZhangQXiaoJZhangK, et al. (2022b) Mechanical behavior of seawater sea-sand recycled concrete columns confined by engineered cementitious composite under eccentric compression. Journal of Building Engineering45: 103497.
33.
ZhangQXiaoJZhangP, et al. (2019) Mechanical behaviour of seawater sea-sand recycled coarse aggregate concrete columns under axial compressive loading. Construction and Building Materials229: 117050.
34.
ZhouYGaoHHuZ, et al. (2021) Ductile, durable, and reliable alternative to FRP bars for reinforcing seawater sea-sand recycled concrete beams: steel/FRP composite bars. Construction and Building Materials269: 121264.
