The present paper reports the testing of 14 OPC-slag mortars and 2 controls OPC and slag mortars. The main aim is to determine the optimum level of replacement slag for achievement to the highest early strength with r...The present paper reports the testing of 14 OPC-slag mortars and 2 controls OPC and slag mortars. The main aim is to determine the optimum level of replacement slag for achievement to the highest early strength with reasonable flow. Variable was the level of GGBFS in the binder. In this experimental work, two types of sands were used that are： silica and mining sands. It is determined that the optimum level of replacement slag is 40% and use of silica sand in OPC is preferable to mining sand and reversely, use of mining sand is preferred in GG100 to silica sand. All mortars had W/B and S/B 0.33 and 2.25, respectively.展开更多
In this experimental work, three groups of cement-slag mortars namely OPC, OPC-slag, and slag mortars were made. All were cured in both water and air under room temperature. Strength development was studied up to 90 d...In this experimental work, three groups of cement-slag mortars namely OPC, OPC-slag, and slag mortars were made. All were cured in both water and air under room temperature. Strength development was studied up to 90 days. The mortars were prepared using 0%, 50%, and 100% replacement with slag. The sensitivity for all groups was obtained against the curing regime with the highest being attributed to the slag mortars. The highest and lowest strengths at early ages were attributed to OPC and slag mortars when both were cured in water. The highest and lowest strengths were attributed to OPC-slag and slag mortars at later ages, respectively. The highest strengths for OPC-slag, OPC, and slag mortars were as 72.0, 64.0, and 21.5 MPa at 90 days when the specimens cured in water, respectively. Strength loss was observed for all groups at later ages when cured in air under room temperature. The maximum and minimum, of about 8.0% and 1.3%, occurred at 56 and 90 days for slag and OPC-slag mortars, respectively.展开更多
The initial hydration of steel slag with high Al2O3 content and its influence on the initial hydration of cement were investigated in this study.Steel slag with high Al2O3 content may contain much calcium aluminate mi...The initial hydration of steel slag with high Al2O3 content and its influence on the initial hydration of cement were investigated in this study.Steel slag with high Al2O3 content may contain much calcium aluminate mineral but very little gypsum.The steel slag hydrates much more quickly than cement in the initial hydration period,producing many flake products which have a great influence on the fluidity,initial setting time,and adsorption level of superplasticizer of paste.Replacing part of cement by steel slag with high Al2O3 content can change the hydration condition of calcium aluminate mineral of the cement by decreasing the gypsum to calcium aluminate mineral ratio,resulting in accelerating the hydration rate of calcium aluminate mineral in the initial hydration period.Paste containing steel slag with high Al2O3 content has a shorter initial setting time,higher adsorption level of superplasticizer,and greater loss in fluidity than the pure cement paste.展开更多
文摘The present paper reports the testing of 14 OPC-slag mortars and 2 controls OPC and slag mortars. The main aim is to determine the optimum level of replacement slag for achievement to the highest early strength with reasonable flow. Variable was the level of GGBFS in the binder. In this experimental work, two types of sands were used that are： silica and mining sands. It is determined that the optimum level of replacement slag is 40% and use of silica sand in OPC is preferable to mining sand and reversely, use of mining sand is preferred in GG100 to silica sand. All mortars had W/B and S/B 0.33 and 2.25, respectively.
文摘In this experimental work, three groups of cement-slag mortars namely OPC, OPC-slag, and slag mortars were made. All were cured in both water and air under room temperature. Strength development was studied up to 90 days. The mortars were prepared using 0%, 50%, and 100% replacement with slag. The sensitivity for all groups was obtained against the curing regime with the highest being attributed to the slag mortars. The highest and lowest strengths at early ages were attributed to OPC and slag mortars when both were cured in water. The highest and lowest strengths were attributed to OPC-slag and slag mortars at later ages, respectively. The highest strengths for OPC-slag, OPC, and slag mortars were as 72.0, 64.0, and 21.5 MPa at 90 days when the specimens cured in water, respectively. Strength loss was observed for all groups at later ages when cured in air under room temperature. The maximum and minimum, of about 8.0% and 1.3%, occurred at 56 and 90 days for slag and OPC-slag mortars, respectively.
基金supported by the National Natural Science Foundation of China(Grant No.51108245)the State Key Laboratory of Silicate Materials for Architectures of China(Grant No.SYSJJ2012-10)
文摘The initial hydration of steel slag with high Al2O3 content and its influence on the initial hydration of cement were investigated in this study.Steel slag with high Al2O3 content may contain much calcium aluminate mineral but very little gypsum.The steel slag hydrates much more quickly than cement in the initial hydration period,producing many flake products which have a great influence on the fluidity,initial setting time,and adsorption level of superplasticizer of paste.Replacing part of cement by steel slag with high Al2O3 content can change the hydration condition of calcium aluminate mineral of the cement by decreasing the gypsum to calcium aluminate mineral ratio,resulting in accelerating the hydration rate of calcium aluminate mineral in the initial hydration period.Paste containing steel slag with high Al2O3 content has a shorter initial setting time,higher adsorption level of superplasticizer,and greater loss in fluidity than the pure cement paste.
