Straw Cement Base Composite Material Performance Research

Alkali activated slag fly ash cementitious materials(hereinafter referred to as the alkali slag fly ash cementitious materials)has been a research hotspot,because the material has excellent mechanical properties,durability and environmental protection etc.and are widely recognized as a substitute material of cement,and the straw is in China there are a lot of renewable resources.But because the utilization rate is extremely low and most burns caused serious air pollution.This paper take advantage of properties of alkali slag and fly ash cement and straw combined with each other,to obtain excellent performance products and for the construction of a resource-saving society contribute in,meet the requirements of China's sustainable development strategy.In this paper,the mechanical properties of alkali slag fly ash cement were studied,and the environmental stability,thermal insulation property and setting time of the composite material were discussed:The primary and secondary order of the factors affecting the strength of alkali activated slag fly ash cement is the proportion of slag and fly ash the total amount of alkali activator cement clinker NaOH and the ratio of water glass.According to the orthogonal experimental design,the optimum mix proportion was determined.It was found that the ratio of slag and fly ash was 3:1 and the total amount of alkali activator was 15%.Through the optimization of the strength performance of alkali slag fly ash cement,it is found that the time of the silica fume,diatomite,the modulus of water glass and the grinding time of fly ash and slag have a certain effect on the strength of cementitious materials.The study found that when the grinding time is 10 min and the strength of silica fume content in 10% when the cementitious material is best;best diatomite as active admixture is under the condition of 600 DEG C calcined 2h,and use 5min to 10% after grinding incorporation on the strength and improve the effect of the best dosage added in cementitious materials modulus of water glass;in between 1.5-1.9 strength of cementitious materials increased more than 2,the strength decreased,decline reason and mechanism is worthy of further study.The straw alkali activated slag fly ash cement stability were studied,including straw material is divided into the surface of carbonized straw bast and NaOH soaked straw,straw and straw bast Bast Pulp,found in the compressive strength,with the increase of straw content,the compressive strength of cementitious materials are decreased gradually.The trend,but the flexural strength was first increased slightly and then decreased,while the effect of the same trend but after surface treatment compared with untreated,the strength decreased relatively slowly,and after the surface carbon of straw bast had the best effect for straw pulp,strength decreased greatly,when the content of 10% at the same time,straw flesh is the strength of the cement is down to 3.4MPa,while the other straw bast remained at more than 10 MPa,so the straw pulp on glue Influence mechanical properties of cementitious materials;the frost resistance of cementitious materials mixed with raw straw bast can withstand 35 times of freeze-thaw cycle,the incorporation of NaOH treated straw can withstand 45 times of freeze-thaw cycle,while the incorporation of surface carbonization straw can withstand 60 times of freeze-thaw cycle,fully shows that the surface of carbide the best treatment effect of straw.The insulation performance of straw and straw Bast Pulp on alkali slag fly ash cement has greatly improved,with the increase of straw pulp and straw bast content,straw alkali activated slag fly ash cement thermal conductivity was gradually decreased,when the content is 10%,the coefficient of thermal conductivity by adding raw straw bast glue cementitious material is 0.1145W/m K,and the thermal conductivity of cementitious materials mixed with straw pulp is 0.1088W/m K,coefficient of thermal conductivity has been decreased,also shows that in the insulation performance of straw pulp is better than straw bast,but strength is worse than straw bast.Straw after grinding can be used as retarder to adjust the setting time of alkali activated slag cement and fly ash,silica fume compound use not only improved the agglomeration phenomenon of straw grinding,also activated slag fly ash cementitious materials on the setting time and strength of alkali have beneficial effects,and studies show that,in addition the conditions are right under the slow coagulation time of straw can be controlled in a certain range,and no significant negative effect on the strength.