Efficiency Of Cement Grinding Aids And Their Application Performance Study

Adding grinding aids in the grinding process could decrease the energy consumption and promote grinding efficiency.It's one of effective and familiar method.In the thesis,grinding effect is considered as the root.Grinding effect is tested according to JC/T 667-2004"The cement grinding aids".Several surface active agents containing hydroxyl,acid amide,carboxyl,sulfuric acid group etc.and complex inorganic matter are used as grinding aids.The main research results are as follows:Firstly,it is found that the mixed amount of single-component grinding aids plays an important role on the grindability of cement after researching kinds of single-component grinding aids with different active groups.The optimal amount of triethanolamine,acetamide,glycol,polycarboxylate and complex inorganic salts was 0.03%,0.04%,0.06%,0.02%and0.08%,respectively.The accelerating effect of triethanolamine,acetamide and glycol is obvious.Triethanolamine,polycarboxylate and complex inorganic salts can improve the long-term strength effectively.The physical properties of cement were not influenced by single-component grinding aids.Secondly,according to the investigation on the complex of single-component grinding aids,a high efficiency grinding aids with better grinding effect is found at the normal temperature and pressure,namely 0.01%triethanolamine,0.01%complex inorganic salts,0.01%polycarboxylate whose usage concentration is 20%.Compared with blank sample,it has good grinding effect.45μm sieving residue of the sample reduces by 6.9%.In the industrial tests,it can improve the particle fineness,and enables 45μm sieving residue decrease by 9.6%.The amount of 10～30μm particles increase 3.66%by optimizing the properties of powers.Both of 3d and 28d compressive strength increase by 3MPa.The maximum adding amount of mineral admixtures can increase by 10.36%.This will cut down the production cost,and enhance the economic benefits.Thirdly,the effect of addition of grinding aids which is studied by XRD and SEM has not change the kind of hydration product.The initial fluidity of the cement paste increases by about 15mm on an average in the incorporation with the same amount of superplasticizer.And the average values of fluidity loss both decrease about 17.5mm after 30 minutes and 60 minutes respectively.Grinding aids can improve the compatibility of cement with plasticizer in the process of concrete usage.