SAP对再生混凝土的抗裂性能影响研究  

Study on the influence of SAP on the crack resistance of recycled concrete

作　　者：周静海[1] 吴晓鑫 赵琦 林东野 赵丽 ZHOU Jinghai;WU Xiaoxin;ZHAO Qi;LIN Dongye;ZHAO Li(School of Civil Engineering,Shenyang Jianzhu University,Shenyang 110168,China)

机构地区：[1]沈阳建筑大学土木工程学院,辽宁沈阳110168

出　　处：《混凝土》2023年第3期110-115,共6页Concrete

基　　金：国家自然科学基金(51678374);辽宁省高等学校创新团队(LT2019011)。

摘　　要：收缩开裂是困扰再生混凝土性能的突出问题之一,探讨掺入超强吸水树脂(SAP)对于再生混凝土的抗裂性能的影响。通过平板抗裂试验研究了不同再生骨料取代率(0、50%、100%)、不同SAP掺量(0、0.1%、0.2%、0.4%)对再生混凝土抗裂性能的影响。采用扫描电镜(SEM)试验对3、28 d龄期下的50%再生骨料替代率的SAP再生混凝土进行了微观分析,探讨了SAP对再生混凝土的阻裂机理。试验结果表明:掺入SAP可有效缓解再生混凝土出现的开裂现象。当SAP掺量为0.2%时,平均开裂面积减小了39.06%,单位面积上的总开裂面积减少了63.62%,效果最佳。掺入SAP后的水泥水化程度有所提高,提高了再生混凝土的内部湿度,改善再生混凝土内部的结构,提高其内部的致密性,提高了再生混凝土的抗裂性能。Shrinkage cracking is one of the prominent problems that plague the performance of recycled concrete.This paper discusses the influence of super absorbent polymer(SAP)on the crack resistance of recycled concrete.The effect of different recycled aggregate replacement rates(0,50%,100%)and different dosages of SAP(0,0.1%,0.2%,0.4%)on the crack resistance performance of recycled concrete was studied through flat-plate crack resistance tests.A scanning electron microscope(SEM)test was used to micro-analyze the SAP recycled concrete with 50%recycled aggregate replacement rate of 3d and 28d,and explore the crack resistance mechanism of SAP on recycled concrete.The experimental results show that the addition of SAP can effectively alleviate the cracking phenomenon that occurs in recycled concrete.When the dosage of SAP is 0.2%,the average cracking area is reduced by 39.06%,and the total cracking area per unit area is reduced by 63.62%,which is the best effect.The degree of cement hydration after mixing with SAP is increased,the internal humidity of recycled concrete is increased,the internal structure of recycled concrete is improved,its internal compactness is improved,and the crack resistance of recycled concrete is improved.

关 键 词：再生混凝土 SAP 抗裂性能 平板抗裂试验 SEM 开裂面积 

分 类 号：TU528.041[建筑科学—建筑技术科学]