低温条件施工对水泥混凝土路面质量的影响

水泥混凝土路面是典型的板状结构,浇筑时混凝土的温度、基层温度、模板温度、环境温度、相对湿度以及风速等对混凝土的浇筑、压实、饰面以及长期路用性能影响较大.低温条件对早期混凝土质量如工作性、凝结时间和早期强度以及体积稳定性和耐久性的影响不可忽视.在总结低温条件对混凝土质量影响的基础上,认为控制混凝土的浇筑温度和浇筑后数日的养护温度对路面的长期性能至关重要.对目前通常采用的控制混凝土浇筑时温度的措施如改善配合比、提高混凝土组分温度、掺加特种外加剂和采取合理的养护措施等作了详细介绍.

Impacts of cold weather on the qualities of portland cement concrete pavement

The impacts of concrete mixture temperature, subgrade temperature, formwork temperature, ambient temperature, relative humidity, and wind speed on concrete placement, compaction, finishing and the long-term properties are significant, especially for Portland cement concrete pavement a typical slab structure.The influence of cold weather on early-age concrete qualities such as workability, setting time, early age strength, long term strength, volumetric stability and durability can not be ignored.The significance of controlling the concrete placement temperature, and the curing temperature during the successive several days just after the placement for the long-term performances can not be over-emphasized, based on the conclusions of the cold weather around the pavement effects on concrete early-age and long-term qualities.The current methods of controlling concrete placement and curing temperature such as modifying of concrete proportion, increasing the temperature of concrete ingredients, adding some special additives, taking some effective curing and protection measures are presented in detail.