高海拔、高寒地区C80高强混凝土配合比设计理论的研究

The design theory for mixing ratio of C80 high performance concrete at high altitude alpine region

为了研究适合青藏高原的环境特征并满足工程要求的C80高强混凝土最佳配合比,采用当地硅酸盐水泥、不同的水胶比、掺合料及高效减水剂等配制C80高强混凝土,通过试验室内对比试验,在同一水胶比的情况下,分析不同掺合料用量及养护龄期对混凝土强度的影响规律,得出掺合料最佳掺量比。结果表明:粉煤灰和硅粉的掺量比对混凝土的强度影响很大,当比例为16.1∶7.1时,混凝土的强度最高。混凝土的抗压强度随养护龄期的增长呈非线性增长,并且曲线在早期增长较快,之后增长速率逐渐变小。

In order to optimize the mixture ratio of C80 high performance concrete that fits the environmental characteristics of the Qinghai Tibet Plateau and meets the engineering requirements,using local portland cement,different ratio of water and cement,admixture and high performance water reducing agent to compound C80 high performance concrete. The indoor experiment test was carried out to investigate the effect of different ratio of fly ash and silica and curing period on concrete strength under the same water-cement ratio. The optimum mixture ratio of fly ash and silica was obtained. The results showed that the ratio of fly ash and silica has much effect on compressive strength. When the ratio is 16. 1 ∶ 7. 1,the compressive strength is the highest. The compressive strength of concrete increases with the curing period,and the curve growth is faster in the early. The growth rate becomes smaller and smaller,finally trends to zero.