绿色生态混凝土碳化降碱技术研究

Research on Alkalinity Reduction of Green Eco-Concrete by Carbonization

绿色生态混凝土的碱度是决定植物生长性的关键因素.分别采用快速碳化和自然碳化两种方法,研究掺加不同掺量矿物掺合料的绿色生态混凝土的碱度和抗压强度的变化规律.试验结果表明:随着碳化龄期的增加,绿色生态混凝土的pH值逐渐降低.快速碳化比自然碳化成果更为显著,快速碳化28d后的pH值降低至8.9,而抗压强度有小幅增强.当矿物掺合料掺量增加到30%,绿色生态混凝土经快速碳化后pH值降低幅度更大,其中粉煤灰效果更好.因此,适量矿物掺合料与快速碳化耦合的降碱技术是可行的,为绿色生态混凝土的推广应用提供了科学的技术指导.

The alkalinity of green eco-concrete is the key element that determines the growth of plants.The changes rule of alkalinity and compressive strength of green eco-concrete mixed with different mineral admixtures were studied by two methods：accelerated carbonation and natural carbonation.The experimental results showed that the pH value of green eco-concrete decreased with the increase of carbonization age.The effect of accelerated carbonation was more significant than natural carbonation,the value of pH decreased to 8.9,and the compressive strength increased slightly after 28 days.When the content of mineral admixture was increased to 30%,the pH value of green eco-concrete was decreased with more extent by accelerated carbonization,and the effect of fly ash was better.Therefore,it is feasible to apply the alkali reduction technology with the right amount of mineral admixture and accelerated carbonation,and it can provide a scientific and technical guidance for the promotion of green eco-concrete.