通过快速碳化试验,综合考虑水胶比、掺合料种类、掺量等因素,对掺合料混凝土碳化规律进行了研究。结果表明:低水胶比是保证掺合料混凝土具有较高抗碳化能力的重要手段之一。掺合料总掺量相同时,掺合料混凝土抗碳化能力从高到低依次为:三掺粉煤灰+矿渣+硅灰,双掺粉煤灰+矿渣,双掺粉煤灰+硅灰,单掺矿渣,单掺粉煤灰,单掺硅灰。合理双掺粉煤灰+矿渣或三掺粉煤灰+矿渣+硅灰,不仅能使混凝土获得满足要求的抗碳化能力,还可以大大提高水泥取代量。
The accelerated carbonation test was carried out at various water-binder ratios, admixture types and admixture replacement. The results show that a lower water-binder ratio is one of the important means to improve the carbonation resistance of concrete containing mineral admixtures (fly ash (FA), ground granulted blastfurnace slag (GGBS), silica fume (SF)). As total amounts of admixtures are equivalent, the carbonation resistance of admixture concretes from high to low is as follows: FA+GGBS+SF, FA+GGBS, FA+SF, GGBS, FA, SF. The carbonation resistance of concrete can meet the requirement in application. The cement replacement can be greatly increased when FA, GGBS and SF are incorporated into concrete.