This study aims to investigate the feasibility of using decoration waste powder(DWP)as a partial replacement for fly ash(FA)in the preparation of geopolymer masonry mortar,and to examine the effect of different DWP re...This study aims to investigate the feasibility of using decoration waste powder(DWP)as a partial replacement for fly ash(FA)in the preparation of geopolymer masonry mortar,and to examine the effect of different DWP replacement rates(0%-40%)on the fresh and mechanical properties of the mortar.The results showed that each group of geopolymer masonry mortar exhibited excellent water retention performance,with a water retention rate of 100%,which was due to the unique geopolymer mortar system and high viscosity of the alkaline activator solution.Compared to the control group,the flowability of the mortar containing lower contents of DWP(10%and 20%)was higher.However,as the DWP replacement rate further increased,the flowability gradually decreased.The DWP could absorb the free water in the reaction system of geopolymer mortar,thereby limiting the occurrence of geopolymerization reaction.The incorporation of DWP in the mortar resulted in a decrease in compressive strength compared to the mortar without DWP.However,even at a replacement rate of 40%,the compressive strength of the mortar still exceeded 15 MPa,which met the requirements of the masonry mortar.It was feasible to use DWP in the geopolymer masonry mortar.Although the addition of DWP caused some performance loss,it did not affect its usability.展开更多
Crushed Ghanaian limestone (L) powder was analysed for its physical, chemical and microstructural properties for the formulation of mortar for masonry. Ordinary Portland Cement (OPC) was replaced by 10- 40% limest...Crushed Ghanaian limestone (L) powder was analysed for its physical, chemical and microstructural properties for the formulation of mortar for masonry. Ordinary Portland Cement (OPC) was replaced by 10- 40% limestone powder for paste and mortar formulation. Mechanical properties that included compressive strength, water demand and setting times (initial and final) were determined and analysed. The mechanical properties were determined in accordance with ASTM standards. The test results indicated that crushed limestone powder contained about 88.7% CaO in calcite form. A 10-30% and 35-40% limestone content in conjunction with OPC was suitable to produce ASTM type M and S mortars respectively. Formulated OPC - L paste showed a high water demand, a delayed initial setting time and an accelerated final setting time than the plain OPC paste.展开更多
The paper investigates the behaviour against corrosion offered by seven masonry mortar compositions to the reinforcement placed in masonry bed joints. Durability protection was evaluated on the basis of four criteria:...The paper investigates the behaviour against corrosion offered by seven masonry mortar compositions to the reinforcement placed in masonry bed joints. Durability protection was evaluated on the basis of four criteria: carbonation area of the specimens, mass loss of steel, electrochemical potential and presence of chloride ions. Tests were performed against two corrosive environments, with and without chloride ions, and were carried out for three periods: three, six and thirty three months. Two types of steel were used, plain steel and galvanized steel. Moreover, the steel protective action of a corrosion inhibitor, sodium nitrite, was examined. A qualitative comparison approach against prototype concrete-like mortars was used. The results showed that the selected masonry mortars did not exhibit similar properties against corrosion to those of concrete and that the addition of sodium nitrite decrease of the corrosion rate only 5% - 20% did not meaningfully improve durability properties. Nevertheless, the addition of lime in small quantities did not have a negative impact on the mortars’ durability characteristics, e.g. the same average corrosion rate.展开更多
基金Funded by the National Natural Science Foundation of China(No.52008046)Young Elite Scientists Sponsorship Program from JSAST(No.TJ-2023-024)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_2848)。
文摘This study aims to investigate the feasibility of using decoration waste powder(DWP)as a partial replacement for fly ash(FA)in the preparation of geopolymer masonry mortar,and to examine the effect of different DWP replacement rates(0%-40%)on the fresh and mechanical properties of the mortar.The results showed that each group of geopolymer masonry mortar exhibited excellent water retention performance,with a water retention rate of 100%,which was due to the unique geopolymer mortar system and high viscosity of the alkaline activator solution.Compared to the control group,the flowability of the mortar containing lower contents of DWP(10%and 20%)was higher.However,as the DWP replacement rate further increased,the flowability gradually decreased.The DWP could absorb the free water in the reaction system of geopolymer mortar,thereby limiting the occurrence of geopolymerization reaction.The incorporation of DWP in the mortar resulted in a decrease in compressive strength compared to the mortar without DWP.However,even at a replacement rate of 40%,the compressive strength of the mortar still exceeded 15 MPa,which met the requirements of the masonry mortar.It was feasible to use DWP in the geopolymer masonry mortar.Although the addition of DWP caused some performance loss,it did not affect its usability.
文摘Crushed Ghanaian limestone (L) powder was analysed for its physical, chemical and microstructural properties for the formulation of mortar for masonry. Ordinary Portland Cement (OPC) was replaced by 10- 40% limestone powder for paste and mortar formulation. Mechanical properties that included compressive strength, water demand and setting times (initial and final) were determined and analysed. The mechanical properties were determined in accordance with ASTM standards. The test results indicated that crushed limestone powder contained about 88.7% CaO in calcite form. A 10-30% and 35-40% limestone content in conjunction with OPC was suitable to produce ASTM type M and S mortars respectively. Formulated OPC - L paste showed a high water demand, a delayed initial setting time and an accelerated final setting time than the plain OPC paste.
文摘The paper investigates the behaviour against corrosion offered by seven masonry mortar compositions to the reinforcement placed in masonry bed joints. Durability protection was evaluated on the basis of four criteria: carbonation area of the specimens, mass loss of steel, electrochemical potential and presence of chloride ions. Tests were performed against two corrosive environments, with and without chloride ions, and were carried out for three periods: three, six and thirty three months. Two types of steel were used, plain steel and galvanized steel. Moreover, the steel protective action of a corrosion inhibitor, sodium nitrite, was examined. A qualitative comparison approach against prototype concrete-like mortars was used. The results showed that the selected masonry mortars did not exhibit similar properties against corrosion to those of concrete and that the addition of sodium nitrite decrease of the corrosion rate only 5% - 20% did not meaningfully improve durability properties. Nevertheless, the addition of lime in small quantities did not have a negative impact on the mortars’ durability characteristics, e.g. the same average corrosion rate.