全轻页岩陶粒混凝土的回弹-超声测强曲线拟合和可靠度分析

Strength testing curve fitting analysis of all-lightweight shale ceramsite concrete

利用回弹法、超声法对全轻页岩陶粒混凝土试块进行平均回弹值Rm、平均碳化深度ml和平均声速值mv的测量,再对混凝土试块进行抗压试验得到强度值fcu,k。根据试验数据,在不考虑碳化深度情况下,对回弹值和抗压强度进行一元曲线拟合;在考虑碳化深度情况下,对回弹值、碳化深度和抗压强度进行二元曲线拟合,并对两者进行对比分析,找出彼此间的联系;再对声速值和抗压强度进行一元曲线拟合。通过对三种测强曲线方程式进行综合对比分析,最终得到相关系数最大的全轻页岩陶粒混凝土测强曲线方程。在此基础上,对全轻页岩陶粒混凝土强度进行概率统计规律分析,并利用所得规律对测强曲线可靠度进行了计算和分析。结果表明:全轻混凝土强度的离散性很大;全轻混凝土强度的概型分布符合正态分布;相关系数最大的测强曲线可靠度为94%,可作为最优测强曲线。

The average rebound value Rm,the average carbonization depth mland the average sound velocity value mvof the all-lightweight shale ceramsite concrete block were measured by rebound method and ultrasonic method. Then,the compressive strength of the tested concrete block was tested to obtain the strength value fcu,k. According to the test data,the rebound value and the compressive strength are fitted with unitary regres-sion curve without considering the carbonization depth,and find out the best curve equation. In the case of considering the carbonation depth,the rebound value,the carbonization depth and the compressive strength are fitted with binary regression curve,and the equation of the best curve is found out,through the comparative analysis of unitary regression curve,find out the best fitting curve equation and the relation between each other. The sound velocity value and the compressive strength are fitted with unitary regression curve,and find out the best curve equation. Based on the comprehensive comparative analysis of the three best curve equations,the optimum curve equation of the all-lightweight shale ceramsite concrete is obtained.