施工环境温度对水泥混凝土路面早期应力强度比影响研究

Study on Effect of Construction Ambient Temperature on Early Stress-strength Ratio of Cement Concrete Pavement

针对水泥混凝土面层强度形成阶段的早期开裂问题，基于HIPERPAV软件，选择在0：00，4：00，8：00，12：00，16：00和20：006个时段铺筑混凝土面层，分别测算铺筑72h内相应的施工环境温度对面层弯拉强度和最大应力的影响。结果表明：16：00铺筑的面层10h后强度开始形成，而对于4：00铺筑的面层，这一时间则是19h。面层铺筑后的13～24h是早期开裂的风险高发期，该时段内混凝土强度仍较低，若此时混凝土水化热和环境温度均较高，则结构应力迅速增长，路面随时面临早期开裂风险。因此，面层铺筑时间应避开20：00左右，考虑到白天施工方便等原因，面层的施工时间可选择在16：00之前。若需夜间施工，应选择在22：00以后。

Based on HIPERPAV software, cement concrete surface was paved at 0：00, 4：00, 8：00, 12：00 , 16：00 and 20：00 , and effect of construction ambient temperature on flexural-tensile strength and the maximum stress of cement concrete surface within 72 hours was determined for its early cracking problems in the stage of forming strength. The results showed that： the strength of pavement began to form after 10hours, if the pavement was poured at 4PM, while this time was 19 hours later, if pavement was poured at 4AM. The interval 13 to 24 hours after paving was a high risk period for surface because of early cracking. In this period, concrete strength was still low. If both the concrete hydration heat and ambient temperatures are at a high level at this time, structural stress would grow rapidly, and pavement would face the risk of cracking at any time. Therefore, the paving time of concrete surface should avoid at night around 8PM, give priority to 0：00~ 4：00. Taking into account that construction easier in daytime, the construction time of surface can be selected before 4PM.