Experimental Research On Compressive Strength And Carbonation Performance Of Aeolian Sand Concrete In Northern Shaanxi

Since the national ban on mining river sands,the widely distributed aeolian sand in northern Shaanxi has become a new source of construction sand.However,the research on the carbonation resistance and durability of aeolian sand concrete in the northern Shaanxi area is very weak,which has seriously affected the aeolian sand in Large-scale use in actual engineering.In this paper,the surface aeolian sand of northern Shaanxi is used as the raw material for the trial preparation of concrete to determine the replacement rate of aeolian sand concrete with the best working performance and mechanical properties.Based on the optimal replacement rate,a combination of indoor rapid test and natural exposure test was used to study the deterioration performance of the durability of aeolian sand concrete under carbonation and alternating effects.Through the indoor rapid carbonization test,analyze the deterioration rules of the durability of aeolian sand concrete under carbonization and joint action,clarify the degradation mechanism from the mechanical,physical and chemical perspectives,and propose a calculation model for the anti-carbonization performance of aeolian sand concrete in northern Shaanxi.The research results of this paper can broaden the source of construction sand in northern Shaanxi,and provide scientific basis and theoretical guidance value for the good application of aeolian sand in urban engineering construction and ecological environment construction.In this paper,the effects of different aeolian sand replacement rates(0,30%,60%and 100%)on the compressive strength of concrete were studied.Through the compressive strength test,the optimal replacement rate of aeolian sand concrete was established.The variation law of compressive strength of aeolian sand concrete under different aeolian sand content was studied,and the variation law of aeolian sand concrete compressive strength with time and aeolian sand content was analyzed.The research results show that the amount of aeolian sand has a significant effect on the compressive strength of concrete.Under a certain sand rate,the compressive strength of aeolian sand concrete with different contents is 30%in order from large to small.,The admixture is 60%,the admixture is 0%and the admixture is 100%.Except for ordinary concrete,the compressive strength of aeolian sand concrete with an admixture of 30%is the largest.As the amount of aeolian sand increases,the compressive strength of aeolian sand concrete increases first and then decreases.In addition,the effect of different aeolian sand replacement rates(0,30%,60%and 100%)on the carbonation depth of concrete under the optimal replacement rate was studied,and the compressive strength of aeolian sand concrete was verified through the carbonization test Whether the optimal replacement rate conforms to the optimal replacement rate of carbonization performance.The variation law of carbonation depth of aeolian sand concrete under different aeolian sand content was studied,and the variation law of aeolian sand concrete carbonation depth with time and aeolian sand content was analyzed.The research results show that the amount of aeolian sand has a significant effect on the carbonation depth of concrete.Under a certain sand rate,the carbonation depth of aeolian sand concrete with different contents varies from large to small in the order of 30%and admixture.The amount of 60%,the amount of 0%and the amount of 100%,except for ordinary concrete,the carbonation depth of the aeolian sand concrete with the amount of 30%is the smallest.As the amount of aeolian sand increases,the carbonation depth of aeolian sand concrete decreases first and then increases.In addition,through regression analysis,the aeolian sand concrete carbonation prediction model was established,and the aeolian product was fitted by experimental results.The sand concrete carbonation depth model verified the model,and the test results were in good agreement with the model calculation results.And the life prediction of aeolian sand concrete under the optimal mix ratio is carried out.The life prediction results show that when the sand rate is 45%and the aeolian sand replacement rate is 30%,the service life can reach 114 years.The research results of this paper can provide a reference for the research on carbonation performance of aeolian sand concrete.