Li Chunbao, Li Xiaotian, Li Shen, Guan Di, Xiao Chang, Xu Yanyan, Soloveva Valentina Y, Dalerjon Hojiboev, Qin Pengju, Liu Xiaohui
College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Construction Project Management Branch of China National Petroleum Pipeline Network Group Co., Ltd., Langfang 065001, China.
Polymers (Basel). 2022 Jul 1;14(13):2703. doi: 10.3390/polym14132703.
This is a study on how to reduce shrinkage and improve crack resistance of foamed concrete. By selecting different curing temperatures and humidity, six different curing conditions were analyzed. The shrinkage deformation and maximum crack width of foamed concrete blocks with water-cement ratios of 0.4 and 0.5, under six curing conditions, were measured by a comparator and optical microscope, and the cracking time was recorded. The effects of curing temperature, humidity and water-cement ratio on the shrinkage and crack resistance of the foamed concrete were analyzed by comparing the experimental results of each group. We studied the primary and secondary order of the three factors affecting the drying shrinkage of foamed concrete. The results show that: temperature is the primary factor that changes the drying shrinkage performance of foamed concrete, followed by the water-cement ratio, and finally humidity. The interaction of these three factors is not obvious. The shrinkage of foamed concrete increases with the increase in temperature; increasing the humidity of curing can control the water loss rate of foamed concrete and reduce shrinkage. Lower humidity and higher temperature will make cracks appear earlier; with an increase in the water-cement ratio, the initial cracking time is shortened and the cracking property of foamed concrete is improved.
这是一项关于如何减少泡沫混凝土收缩并提高其抗裂性的研究。通过选择不同的养护温度和湿度，分析了六种不同的养护条件。采用比较仪和光学显微镜测量了水灰比为0.4和0.5的泡沫混凝土砌块在六种养护条件下的收缩变形和最大裂缝宽度，并记录了开裂时间。通过比较每组的实验结果，分析了养护温度、湿度和水灰比对泡沫混凝土收缩和抗裂性的影响。研究了影响泡沫混凝土干燥收缩的三个因素的主次顺序。结果表明：温度是改变泡沫混凝土干燥收缩性能的主要因素，其次是水灰比，最后是湿度。这三个因素的相互作用不明显。泡沫混凝土的收缩随温度升高而增大；提高养护湿度可控制泡沫混凝土的失水率并减少收缩。较低的湿度和较高的温度会使裂缝出现得更早；随着水灰比的增加，初始开裂时间缩短，泡沫混凝土的开裂性能提高。
