摘要
纳米材料具备促进水泥水化、改善混凝土力学性能及提高混凝土耐久性等潜能,在水泥混凝土中的应用得到广泛关注。将纳米碳酸钙采用常规分散方式掺入普通水泥混凝土中,以期改善混凝土的各项性能,并为纳米碳酸钙在水泥混凝土中的规模化应用提供参考。研究了常规分散方式下不同纳米碳酸钙掺量对水泥混凝土工作性能及力学性能的影响,测试了掺入纳米碳酸钙后各组混凝土的抗冻融循环性能、抗碳化能力及干燥收缩等耐久性指标,并系统分析了纳米碳酸钙的掺入对水泥混凝土工作性、力学性能、耐久性的影响机理。研究结果表明:纳米碳酸钙以常规分散方式加入,在掺量适宜的条件下,可以明显改善水泥混凝土的流动性,提高混凝土的强度,降低混凝土的压折比,增强混凝土的韧性;还会对水泥混凝土的耐久性产生一定的影响,增强了混凝土的抗冻融循环性能和抗碳化能力,但也会导致混凝土的干燥收缩值略有增大。采用常规分散方式向水泥混凝土中掺入纳米碳酸钙,其掺量不宜超过胶凝材料质量的1.0%。若掺量过高,将显著降低水泥混凝土的流动性、力学性能及耐久性。
Utilization of nanomaterials in concrete has been gainingwidespread attention as it exhibits potential of accelerating thehydration of cement,improving the mechanical property and the durabilityof concrete. Nano-CaCO3 is adopted into portland cement concrete withconventional dispersion method to improve concrete performance. It canprovide the reference for the large-scale application of nanomaterialsin cement concrete. The influences of different Nano-CaCO3 contents onthe workability and mechanical properties of cement concrete withconventional dispersion method are investigated. The durabilityindicators,such as freeze-thaw resistance,anti-carbonization and dryingshrinkage of the concrete with different Nano-CaCO3 contents are alsotested. The influence mechanism of adding Nano-CaCO3 onworkability,mechanical property and durability are also studied. Theresult shows that(1) the suitable dosage of nano-CaCO3 is adopted intocement concrete with conventional dispersion method,thus the fluidity isimproved remarkably,the strength is improved,the ratio of compressivestrength to flexural strength is reduced,and the toughness isincreased;(2) the addition of Nano-CaCO3 has an impact on the durabilityof concrete,the frost resistance and carbonation resistance areeffectively reinforced,while the drying shrinkage of concrete isincreased slightly;(3) the addition dosage of Nano-CaCO3 into cementconcrete with conventional dispersion method should not exceed 1.0% ofcementitious material weight,otherwise the flowability,the mechanicalproperty and the durability of cement concrete will be significantlydecreased.
作者
明杏芬
明晓东
MING Xing-fen;MING Xiao-dong(School of Civil Engineering, Wuchang Institute of Technology, Wuhan Hubei 430065, China;Country Garden Holdings Co., Ltd., Kunming Yunnan 650000, China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2019年第6期25-30,共6页
Journal of Highway and Transportation Research and Development
基金
武昌工学院校级资助重点课题项目(2015KYZ02)
武昌工学院科研团队“路桥基础动力响应机理及稳定性研究”项目(2017T03)
