Modification Of Zeolite Powder And Experimental Study On Humidity Controlling And Mechanical Properties Of Humidity Controlling Materials Based On Zeolite

Air humidity is the amount of water vapor in a certain volume of air at a certain temperature,which directly affects people's comfort,so the control of air humidity is closely related to human life.At present,the methods of regulating humidity include active and passive methods.The active humidity control means air conditioning technology,which needs to consume energy and causes air pollution.Passive humidity control means using humidity control materials to control humidity.This method neither consumes any energy nor produces pollution.It is an environment-friendly way of humidity control.Zeolites is a passive humidity controlling material,which has many internal viods,large specific surface area,good adsorption performance and is easy to access at low cost.It can be widely used to humidity control building materials.In this paper,the methods of heat treatment,inorganic salt solution modification and comprehensive were used to improve the humidity control performance of zeolite powder.In the experiment,the zeolite powder with excellent humidity control performance was be selected to replace the cement to put into mortar and concrete.The humidity control performance of humidity controlling material based on zeolite was evaluated by the capacity of isothermal absorption and the absorption and desorption rate and the capacity of cycle humidity absorption and desorption.The mechanical properties and construction performance experiment of humidity controlling material based on zeolite with different content were carried out.The building materials based on zeolite with the excellent humidity control and mechanical properties were selected by the experiment of humidity control performance and mechanical performance experiment.The experiment results show that:(1)The humidity control performance was improved by modification of the zeolite powder,and the result of the modification of salt solution was better than that of heat treatment.The performance of zeolite powder modified by twenty-five percent NaCl solution was the best.On the basis of the modification of salt solution,it can be improved again by the heat treatment of zeolite powder.The effect of the modified by twenty-five percent solution and two hundred celsius treatment for one hour was the most obvious,and the maximum moisture absorption was six point four times that of original zeolite powder.(2)In the construction performance experiment of mortar mixing with zeolite powder,with the addition of the content of zeolite powder,the consistency of mortar gradually decreased,and the water retention rate of mortar increased gradually.When the content of zeolite powder is ten percent,the compressive strength of mortar is highest in all samples,it is higher than that of ordinary mortar.When the content of zeolite powder is higher than ten percent,the compressive strength of mortar decreases with the addition of the content of zeolite powder.The flexural strength of mortar mixed with zeolite powder decreases with the increase of zeolite dosage.In the mechanical performance experiment of concrete mixing with zeolite powder,When the content of zeolite powder is ten percent,the compressive strength and the flexural strength of concrete is highest in all samples,it is higher than that of ordinary concrete.When the content of zeolite powder is higher than twenty percent,the compressive strength and the flexural strength of concrete decreases with the addition of the content of zeolite powder.(3)The moisture absorption performance of humidity controlling material based on zeolite powder increased with the increase of the content of zeolite powder in the absorption test;in the cycle humidity absorption and desorption test,the humidity control performance of the humidity controlling material based on zeolite powder had little reduction,but the attenuation was not large,it proves that the humidity controlling material based on zeolite powder has a sustainable humidity controlling capability.Through isothermal absorption test,the moisture absorption isotherms of different zeolite powder samples were obtained.Fitting the equation with the moisture absorption isotherms,it was found that the result of using the ETC and CQG formula is more consistent with experimental results than that of FSEC.