养生温湿度条件对路面水泥混凝土弯拉强度的影响

Effect of Curing Temperature and Humidity Conditions on Flexural Tensile Strength of Pavement Cement Concrete

采用复合力学理论,建立混凝土弯拉强度随龄期增长全过程分析模型。与水泥水化动力学相结合,建立了养生温度和湿度条件下水泥混凝土弯拉强度发展的预估模型,通过试验数据回归分析对不同养生条件下弯拉强度预估模型进行了验证,模型预测结果与实测结果基本相符。研究结果表明,相对湿度越低,各龄期混凝土弯拉强度越低,弯拉强度差异随着龄期增长而变大。初始水灰比大于0.39,则水分蒸发损失对强度的影响减小。据此确定了养生工艺参数,结合水泥混凝土水分蒸发率分析对养生浇水次数进行了重新计算,根据自然养生条件下强度增长规律计算了养生时间,进而提出了水泥混凝土路面自然养生工艺优化措施。

Based on composite mechanics theory,the model of flexural tensile strength of concrete increasing with age was built.The forecast model of flexural tensile strength developing of cement concrete under the condition of certain curing temperature and curing humidity was built combining with the cement hydration dynamics.Through regression analyzing the test data,the forecast model was verified under different curing conditions,and the prediction result and measured result was basically the same.The result shows that（1） the smaller the relative humidity,the smaller the flexural tensile strength of different ages,and the variability of flexural tensile strength increased with the age growing;（2） if the initial water-cement ratio is more than 0.39,the effect of evaporation loss on strength would be weaker.Based on this,the curing parameters were determined,the frequency of watering was recalculated according to the water evaporation rate of concrete,the curing time was calculated based on the strength development regularity under natural curing condition,and the optimized natural curing technique of cement concrete pavement was put forward according to the calculation.