高性能混凝土工作性及耐久性试验研究

Experimental study on workability and durability performance of high performance concrete

结合福建当地材料,配置C50等级高性能混凝土,研究不同矿物质及掺量对拌合物工作性、劈裂强度及耐久性等影响。试验得到粉煤灰、矿粉在改善拌合物工作性、抗渗性及劈裂强度等指标的较优掺量及影响规律。双掺性能更优,体现了其在粒形级配改善,工作性提高及火山灰效应的复合优势。提出可综合考虑质量变化率、相对动弹性模量及强度等的混凝土损伤程度指标,对混凝土在快速冻融、盐水腐蚀等因素共同作用下的损伤情况进行半定量评估。结果表明,素混凝土损伤程度最大,而矿粉掺量20%和粉煤灰掺量15%的损伤指标明显降低,表明该掺量下混凝土的耐久性能明显提高。

High performance concrete （ materials. Experiments were conducted HPC） C50 was prepared to investigate the effects minerals on the workability, splitting strength in combination with Fujian local and dosages of the added/dosed durability of HPC. The optimal dosages of the miner- als and their effects on improving the workability, impermibiliy and splitting strength of HPC were obtained. Doubly mixed HPC is of better performance in that it has composite advantages of ingrain shape grading, workability and volcano ash effect. Damage index of concrete taking account of mass variation, relative elastic modulus and strength was presented to evaluate semiquantitively the dam- age of concrete under the action of rapid freezing and thawing and salt water corrosion. The results show that the damage index of plain concrete is the highest while the composite with a dosage of 20% slag powder and a dosage of 15% fly ash has a considerably lower damage with significantly improved workability.