Experimental Study On The High-Performance Lining Construction

In recent years, society is strongly advocating " low-carbonlife", adhereing to theroad of sustainable development, realizing the harmonious development of human andnature. If adopting the"green concrete"can not only reducing the dosage of cement,reducing the consumption of resources and reducing the emissions of carbon dioxide,etc, but also can ensure good durability of concrete and prolong the service life ofengineering, reduce maintenance cost.The research is based on"Qingdao Subway-Lining Concrete". By using mineraladmixture including fly ash, slag-general, ultrafine mineral admixture and waterproofadmixture, some performances are improved to obtain high-quality green concrete. Thepaper analyzes three factors on different cementitious systems, that influenced theservice behaviour, mechanical properties and durability of green concrete. Theexperiment involve: 1)Fly ash or slag-general separately replaces 30%,40% or 50%cement；2) Mixing fly ash with slag in 1:1 separately replaces 30%,40% or 50%cement；3)Fly ash and slag separately composite ultrafine mineral admixtures orwaterproof admixture (ultrafine mineral admixtures and waterproof admixture for 10%of the total content) separately replaces 30%,40% or 50% cementThe experimental results indicates as follows: Adopting the green concrete cansignificantly reduce the dosage of cement, comparing with normal weight aggregateconcrete in the same strength class, green concrete can reduce cement about100kg/m3;In the same cementitious system ,the strength of slag concrete is about 1.2-1.3times of fly ash concrete; If mixing fly ash and slag with 1:1, the strength of concrent isabout 1.1-1.3 times of fly ash concrete; If add 10% ultrafine mineral admixture,thestrength of fly ash concrete is elevated to 1.2-1.5 times, the strength of slag concretestrength can achieve benchmark concrete (pure cement) level; The ability of greenconcrete resistance of carbonate carbonation is effectively enhanced by mixinghigh-active mineral admixtures；Fly ash concrent,s anti-cracking ability is superior toslag concrent, the concrent,s anti-cracking ability will be reduced if adding ultrafinemineral admixture, if green concrete have well early curing, it will show excellentcrack-resistance late. In the same cementitious system, the penetration resistance ofchloride ions of slag concrent is far superior to the fly ash series; Fly ash and slag composition or adding high-active mineral admixture, the penetration resistance ofchloride ions of green concrent will be better improved. Based on the systematicexperimental research , a sequence of different cementitious material system, differentstrength grade of concrete proportion are giving, and the result of this study have beenadopted by"Qingdao Subway Engineering".