Due to the relatively high density of conventional non-sintered lightweight aggregate(NLA),a low-density core-shell NLA(CNLA) was developed.Moreover,two types of porous lightweight aggregate concrete (PLAC) for wallbo...Due to the relatively high density of conventional non-sintered lightweight aggregate(NLA),a low-density core-shell NLA(CNLA) was developed.Moreover,two types of porous lightweight aggregate concrete (PLAC) for wallboard were designed,using both foam and lightweight aggregates.The effects of LA on lightweight concrete workability,compressive strength,dry shrinkage,and thermal conductivity were studied and compared.The bulk density of CNLA can be lowered to 500 kg/m^(3),and its cylinder crushing strength is 1.6 MPa.PLACs also have compressive strengths ranging from 7.8 to 11.8 MPa,as well as thermal conductivity coefficients ranging from 0.193 to 0.219 W/(m·K^(-1)).The CNLA bonds better to the paste matrix at the interface transition zone,and CNLA concrete has a superior pore structure than SLA concrete,resulting in a 20% improvement in fluidity,a 10% increase in strength,a 6% reduction in heat conductivity,and an 11% decrease in drying shrinkage.展开更多
This study focuses on the resource utilization of titanium gypsum to explore its potential as a building material.Using titanium gypsum powder as the main raw material,mixed with a certain proportion of cement,silica ...This study focuses on the resource utilization of titanium gypsum to explore its potential as a building material.Using titanium gypsum powder as the main raw material,mixed with a certain proportion of cement,silica fume,activator and binder,etc.,and designs the indoor test scheme of different granulator speed,balling time and curing conditions.The unburned ceramsite with stable structure and reliable strength is prepared.The strength and water absorption index are measured based on the requirements of the standard standard.The results are as follows:(1)By analyzing the aggregate shape coefficient,bulk density and cylinder compressive strength,it is known that the bulk density of the prepared titanium gypsum-coated ceramsite ranges from>900 kg/m³to≤1000 kg/m³(i.e.,900 kg/m³<bulk density≤1000 kg/m³).The apparent density is between 1700-2200 kg/m3,which belongs to 1000 grade artificial aggregate.In the test scheme,only A5,A7 and A8 meet the basic requirements of aggregate.(2)Based on the entropy weight method,the sensitivity analysis of cylinder compressive strength,water absorption and single aggregate bearing capacity of different test groups was carried out.The results showed that the order of influence on the bearing capacity of single aggregate at 14 d age was molding time>rotation speed>curing condition.The order of influence of cylinder compressive strength at 14 d age is molding time>rotational speed>curing condition.The order of influence on the 24-hour water absorption at 14 days of age is molding time>curing condition>rotational speed.This study can provide a basis for resource design.展开更多
基金Funded by the National Key R&D Programs of China (Nos. 2016YFC0701907, 2021YFB3802000 and 2021YFB3802004)。
文摘Due to the relatively high density of conventional non-sintered lightweight aggregate(NLA),a low-density core-shell NLA(CNLA) was developed.Moreover,two types of porous lightweight aggregate concrete (PLAC) for wallboard were designed,using both foam and lightweight aggregates.The effects of LA on lightweight concrete workability,compressive strength,dry shrinkage,and thermal conductivity were studied and compared.The bulk density of CNLA can be lowered to 500 kg/m^(3),and its cylinder crushing strength is 1.6 MPa.PLACs also have compressive strengths ranging from 7.8 to 11.8 MPa,as well as thermal conductivity coefficients ranging from 0.193 to 0.219 W/(m·K^(-1)).The CNLA bonds better to the paste matrix at the interface transition zone,and CNLA concrete has a superior pore structure than SLA concrete,resulting in a 20% improvement in fluidity,a 10% increase in strength,a 6% reduction in heat conductivity,and an 11% decrease in drying shrinkage.
基金Zhejiang Provincial Water Science and Technology Program(Grant Nos.RB2513,RA2403,RB2415)for their invaluable financial support and assistance in this research.
文摘This study focuses on the resource utilization of titanium gypsum to explore its potential as a building material.Using titanium gypsum powder as the main raw material,mixed with a certain proportion of cement,silica fume,activator and binder,etc.,and designs the indoor test scheme of different granulator speed,balling time and curing conditions.The unburned ceramsite with stable structure and reliable strength is prepared.The strength and water absorption index are measured based on the requirements of the standard standard.The results are as follows:(1)By analyzing the aggregate shape coefficient,bulk density and cylinder compressive strength,it is known that the bulk density of the prepared titanium gypsum-coated ceramsite ranges from>900 kg/m³to≤1000 kg/m³(i.e.,900 kg/m³<bulk density≤1000 kg/m³).The apparent density is between 1700-2200 kg/m3,which belongs to 1000 grade artificial aggregate.In the test scheme,only A5,A7 and A8 meet the basic requirements of aggregate.(2)Based on the entropy weight method,the sensitivity analysis of cylinder compressive strength,water absorption and single aggregate bearing capacity of different test groups was carried out.The results showed that the order of influence on the bearing capacity of single aggregate at 14 d age was molding time>rotation speed>curing condition.The order of influence of cylinder compressive strength at 14 d age is molding time>rotational speed>curing condition.The order of influence on the 24-hour water absorption at 14 days of age is molding time>curing condition>rotational speed.This study can provide a basis for resource design.
