矿物掺合料对高性能混凝土力学性能和耐久性的影响

【作者】 盛黎；

【导师】 叶青；

【作者基本信息】 浙江工业大学 ， 材料学， 2004， 硕士

【摘要】 本文对矿渣、粉煤灰和膨胀剂以不同比例掺入高性能混凝土后对其力学性能和耐久性能产生的影响进行了论述。研究内容主要包括掺矿物掺合料的高性能混凝土随水胶比，配合比、以及养护条件等因素不同，抗压强度、劈拉强度、抗折强度和弹性模量等力学性能以及干燥收缩、抗氯离子渗透和抗冻性等耐久性能的变化规律。同时结合矿物掺合料的水化机理，阐述了掺合料对混凝土微结构的改善作用以及混凝土高性能化的有效途径。 试验结果表明：(1)掺入矿渣使混凝土早期强度下降，后期强度增大；干缩率下降，抗氯离子渗透能力、抗碳化能力提高。(2)同时掺入粉煤灰和矿渣，后期出现优势互补效应，提高了混凝土的强度；虽然复掺以后混凝土早期干燥收缩率有所增大，但后期增长缓慢，仍然具有较好的耐久性能。(3)UEA膨胀剂掺入后，高性能混凝土早期强度降低，后期强度提高；早期干燥收缩率不但没有减小反而有所增大。(4)养护条件会直接影响掺合料的改性作用，潮湿养护能使掺合料更好的发挥抑制干燥收缩的能力，使膨胀剂真正起到补偿收缩的作用。(5)高性能混凝土受预压后，抗氯离子渗透能力下降，掺膨胀剂的混凝土下降幅度相对较小。更多还原

【Abstract】 In this thesis, the influences of combinations of slag, fly ash and expansive agent at different rations on the mechanical properties and durability of high performance concrete (HPC) were studied. Under the fluctuation of water-binder ration, mix proportion, curing conditions, the variable laws of compressive strength, split tensile strength, flexural strength, elastic modulus, drying shrinkage, chloride permeability, and frost resistance were discussed.The results indicated that slag added to HPC could decrease early strength and drying shrinkage, however, 28-days strength, chloride permeability, carbonization resistance were improved. The dominant complementation effect was showed when the proportion of slag and fly ash was appropriate. Early strength of HPC added with expansive agent decreased, but drying shrinkage was still great. We found it necessary for HPC to prolong the water curing age, which could control drying shrinkage more effectively. After HPC was compressed, chloride permeability was declined.更多还原