路面超薄层罩面的水泥混凝土配合比优化设计

摘要

In this paper,according to the actual construction of cement concrete road,through the rapid repair technology of ultra-thin pavement,cement concrete mix design optimization.The results show that the water cement ratio test shows that,in order to ensure the strength of concrete,the concrete should adopt a smaller water cement ratio,but the water cement ratio should not be too small.The results show that increasing the ratio of water to cement can prolong the initial cracking time of concrete.After adjusting the admixture,the workability of the fresh concrete is improved obviously.In 1H,the slump loss is reduced within 20 mm,which meets the requirements of construction.The greater the water cement ratio,the longer the cracking time of concrete.Through the initial crack to the water cement ratio of 0.36 to 23 min,0.38 to 34 min,there is an optimal concrete water cement ratio in the region exists,within the scope of the water cement ratio,through time and the latest concrete plastic cracking,anti cracking ability is relatively high.Finally,through the strength,workability,plastic shrinkage test,to determine the fly ash content of 10.5％,water to cement ratio of 0.38 when the mixture ratio for the optimal ratio,that is,the ratio of B-2 group for the best ratio.%根据水泥混凝土公路施工实际,通过路面超薄层快速修补技术,进行了水泥混凝土配合比设计的优化研究.结果表明,水灰比试验显示,要保证混凝土强度值,混凝土应采用较小的水灰比,但水灰比不能过小,混凝土在只用当中会存在开裂的风险,这和水泥还有石灰的比例是分不开的.从我们进行过的收缩性的试验来表明,当水泥和石灰的比例增大的时候,混凝土在使用时第一次开裂的时间会被延长.在外加剂的作用下,新拌混凝土各项性能指标得到提升,使每小时的控制坍落度降低至20 mm以下,满足了施工方面所需.水胶比越大,混凝土开裂时间越长.初裂到贯通在水胶比0.36时需要23 min,0.38时需要34 min,通常存在一个最优水胶比区域,在该区域内混凝土的贯通时间和塑性的开裂时间能够进行延长,并且延长的情况是最明显的,这个时候混凝土自身的抵抗开裂能力的情况比较好.在这篇文章当中我们主要是进行几个方面的试验还有证明,得出结论当粉煤灰掺量达到10.5％,且比例为0.38的水胶比时为最优配比,也就是B-2组配比为最优配比.