FRP-再生骨料海砂混凝土组合结构的力学与抗震性能及耐久性研究

The huge demand but increasing shortage of building material resources and the surprising construction waste emission are becoming the major problems that delay the sustainable development of construction industry in China. This proposed research project will thus develop a new type of sustainable green concrete (SGC) composite structure that is constructed from renewable resource of recycled concrete aggregate (RCA), sustainable resource of sea sand, and high-strength and high corrosion-resistant material of Fiber Reinforced Polymer (FRP). A new type of bar that can effectively resist to the corrosion induced by chloride initially contained in sea-sand is also developed by plating a certain thickness of FRP onto the traditional steel bar. This bar has a great superiority of high strength and high corrosion resistance and thus is well suited for reinforcing sea-sand concrete structures. For simplicity, it is called the composite bar hereafter. Experimental studies on the mechanics performance and durability of the composite bar and the bond behaviors between the bar and concrete will be carried out. The tensile/compressive stress-strain constitutive relationship of the bar and the bond-slip constitutive relationship between the bar and concrete will be established, and the durability of the bar will be assessed. On this basis, the proposed research project will further experimentally investigate the basic mechanic, the seismic performance and the durability of composite bar reinforced RCA-sea sand concrete filled FRP tube composite structure. In-depth study of the compression and bending performance, hysteretic behavior, and durability of the composite structure will be conducted which finally leading to further development of the seismic and durability design methodology. The deliverables of the project will contribute to solve the shortage problem of construction material resources and thus help to realize the sustainable development of construction industry.

建筑材料资源需求巨大、建筑材料原生资源日益紧缺与建筑垃圾排放惊人是我国建筑工业发展面临的三大严峻考验。本申请项目拟将资源可再生的再生混凝土骨料、资源可持续的海砂与高强轻质耐腐蚀的纤维增强复合材料（FRP）组合成新型的FRP-再生-海砂混凝土绿色复合材料及组合结构，同时开发一种由FRP及钢筋复合而成的、能免疫海砂中氯离子腐蚀的、高强耐腐蚀的筋材（简称复合筋），用于海砂混凝土结构的增强。项目拟研究复合筋的力学性能、耐久性及其与混凝土的粘结特性，建立复合筋的力学本构及其与再生-海砂混凝土的粘结滑移关系本构；在此基础上，研究复合筋增强FRP管再生骨料海砂混凝土组合构件的力学性能、抗震性能与耐久性，分析组合构件压弯性能、滞回特性与耐久性，建立组合构件的设计理论和方法，以实现再生混凝土骨料、海砂与FRP等绿色建筑材料在土木工程中的高性能化应用，解决建筑资源紧缺与可持续性问题，推动建筑工业的可持续发展。

本项目将再生混凝土骨料、海砂与高强轻质耐腐蚀的纤维复合材料（FRP）组合成新型绿色混凝土复合材料及组合结构，开发高强、耐腐蚀的FRP-钢（筋）复合筋和FRP-钢（管）复合管，研究FRP-复合筋/管-再生骨料海砂混凝土组合结构的基础力学性能、抗震性能及耐久性，以推动再生混凝土骨料、海砂与FRP 等绿色建筑材料在土木工程中的广泛应用，解决建筑资源紧缺与可持续性问题，实现建筑工业的可持续发展，取得了如下研究成果：.（1）开展了FRP-钢复合筋的力学性能和耐久性试验研究，建立了复合筋/管的拉压应力应变本构关系，明确了FRP-复合筋/管的耐腐蚀特性。.（2）开展了纳米二氧化硅（NS）与微米碳酸钙（MC）方法改性再生粗骨料（RCA）混凝土试验研究，分析了再生混凝土（RAC）水化过程、微观结构特征和抗压强度变化情况；选取不同海域的原状海水及海砂为原材料，配制出了海水海砂混凝土，研究了海水海砂混凝土的基本性能。.（3）开展了复合筋与再生骨料海砂混凝土的粘结性能试验研究，分析了纤维种类、表面处理方式、筋材直径及螺纹间距对 FRP-钢复合筋粘结强度的影响。.（4）开发了新型FRP-复合筋-再生骨料海砂混凝土组合构件，建立了组合截面的优化方法；开展了CFRP-绿色混凝土-钢管组合梁抗弯性能试验研究，建立了双管组合梁的受弯承载力模型。.（5）开展了复合筋增强再生骨料海砂混凝土组合柱轴心受压与低周反复荷载作用下的力学性能试验研究，研究了组合柱的基础力学性能与抗震性能，建立了双管组合柱的应力应变模型。.（6）开展了不同种类受力筋（SFCB、CFRP、普通钢筋）增强再生骨料海水海砂混凝土梁抗弯性能试验研究，提出了SFCB增强再生骨料海水海砂混凝土梁的受弯承载能力模型；开展了不同种类受力筋材（C-SFCB、G-SFCB、FRP）增强再生骨料海水海砂混凝土梁长期性能试验研究，分析了组合结构的耐久性。.（7）发表了SCI论文30篇，授权发明专利4项，授权实用新型专利2项；培养硕士研究生6名（5名毕业，1名在读）。