Research On Modified Technology And Performance Of High Calcium Ash And Steel Slag Cementitious

In 2005, large of resources and energy have to be used up for 1.064 billion tons cement production in China, which results in the serious problem about how to develop continually. To result this question, one of effective techniques is to utilize the industrial solid waste as cement admixture or cementitious with special function. which reduces not only consumes of resources and energy, but also industry pollutions else. The shortcomings of Portland cement itself can be resulted by utilizing characteristic of industrial solid waste as while as. Funded by the national 863 project, The key Techniques for Preparation of Low Environment Burthen Type of Cement and Cementitious, high calcium ash (HF) and steel slag(SS) are used to produce high durability cementitious which of workability and durability are studied in this paper.Study results of HF characteristic show that HF prolongs the setting time obviously and blend cement with 50% HF shows abnormally setting, expect high f-CaO and instability of content. Study results of SS characteristic show tha activity of SS is low and compression will fall sharply when SS is more than 30% cementitious, expect instability of content.Uniting calcined phosphorgypsum(CG), tri-ethanolamine with mechanical grinding, HF and SS are actived and form high duribility cementitious, which can substitute for 20%⁵0% of cement to mend duribility of cement and concrete. The mineral activating mechanism is that CG can stimulate pozzolanicity because of higher solubility and looser crystal structure, and has the property on retardation setting;tri-ethanolamine has the properties on inchoate compression and helping grinding;the physical grinding can make HF and SS increase surface acreage and activity and decrease hazardiess of f-CaO.High durability cementitious (MPS) includes calcined phosphorgypsum, HF and SS. with MPS of 50% cement, in 28 days, mortar compression is low, but in 90 days, mortar compression is enhanced obviously. In in three sorts of curing methods of 20 ℃, and tap water curing, 50% RH curing and 5% Na₂SO₄ liquor curing, effect on volume change of mortar with MPS has been stadied and results show that volume shrinkage of mortar has been prevented in 28 days and 90 days. In 28 days, volume of 100% cement mortar is shrinking, but with MPS, volume of mortars are swelling in the three sorts of curing methods. In 90 days, and in tap water curing, shrinkage falls 56.9%;in 50% RH curing, shrinkage falls 28.4%;in 5% Na₂SO₄ liquor curing, shrinkage falls 88.1% and is closed to zero shrinking. In the experiments of chlorine ion penetrating and resisting freezing and thawing circles of concrete, results show that with MPS cementitious, chlorine ion penetrating performance of concrete is only 66.9% of 100% cement sample, and after 100 freezing and thawing circles, module lost is only 29.9% of 100% cement sample.