水泥混凝土成熟度积分计算方法适用性分析

Application Analysis of Maturity Integral Calculation Method for Cement Concrete

室内标准养生条件下确定的水泥混凝土凝结时间与施工现场实际凝结时间差异较大,为了提高凝结时间对水泥混凝土路面施工的指导性,提出了成熟度积分计算方法,分析了采用该方法计算水泥混凝土成熟度的适用性,并通过建立室外自然养生条件下"成熟度—贯入阻力"关系曲线与标准养生条件下"成熟度—贯入阻力"关系曲线,分析了采用成熟度进行水泥混凝土凝结时间预测的精度。试验结果表明:相比于振荡式气温变化情形,水泥混凝土成熟度积分计算方法更适用于增减有致的抛物线式气温变化情形;成熟度—贯入阻力关系灰关联分析表明,积分法与分段法成熟度计算方法精度相当;相比于采用水泥混凝土拌合物凝结时间试验方法确定的水泥混凝土凝结时间,采用该时间对应的成熟度进行凝结时间的预测具有更高的精度。采用成熟度预测凝结时间与水泥混凝土路面实际施工状况更加符合,建议将成熟度作为测试水泥混凝土凝结时间的技术指标。

The difference of setting time measured in laboratory with standard maintenance and construction site for cement concrete was significant. In order to improve guiding of time of setting for cement concrete construction, the application of the maturity integral calculation method for cement concrete was analyzed through the establishment of maturity calculation model based on integral method, and then the accuracy of predicting setting time for cement concrete with ＂maturity-penetration resistance＂relation curve established on outdoor natural maintenance and indoor standard maintenance were compared. The results show that compared with vibrating type of temperature changes, the maturity integral calculation method is more suitable for parabolic type of temperature changes;grey relational analysis of maturity-penetration resistance relationship shows that the integral method of maturity calculation＆amp;nbsp;has quite accuracy compared with the piecewise method;using standard test method for time of setting of concrete mixture by penetration resistance to determine the setting time is not reasonable, and applying the corresponding maturity to predict time of setting shows higher accuracy. Predicting time of setting with maturity conforms preferably to actual institute in cement concrete construction site, and maturity is recommended as technical index of measuring time of setting for cement concrete.