Research On The Application Of Porous Basalt In Building Materials

Porous basalt is widely distributed and has huge reserves.In this manuscripts,according to the principle of local materials,porous basalt is used as building materials,used as fine aggregate and coarse aggregate of concrete,used as cement stabilized macadamia material and aggregate of asphalt mixture.Basalt is a silicate rock formed when magma erupts to cool the ground during volcanic eruptions.It is widely distributed in the bottom of continents and oceans and often has pores and almond structures.Basalt is characterized by high content of iron oxide,stable chemical composition and mineral composition,and low melting temperature.The research contents are as follows:Concrete is the most common material in construction materials.With the development of construction industry,high-quality raw materials of concrete are relatively scarce.Through investigating the research status of porous basalt,it is found that it can be used as concrete aggregate,but it has not been widely used in engineering.Therefore,this topic takes three kinds of porous basalt aggregate with different particle sizes as the main raw materials,and carries out the mix ratio design of C50 by changing the water-binder ratio and fly ash content,etc.,and conducts related research on the influence of the durability of the porous basalt concrete produced by mixing.The results show that porous basalt can prepare C50 concrete.Porous basalt contains a large number of pores,which will have a certain impact on the performance of concrete.Therefore,by changing the dosage of pre-wet porous basalt,the influence of different dosage of pre-wet porous basalt on the performance of concrete is studied.The results show that when the dosage of pre-wet porous basalt is 0,the compressive performance of concrete is the best and the electric flux is the minimum.When the concrete was cured to 28 d and the content of pre-wet porous basalt was 100%,the mechanical properties and chloride ion penetration resistance of concrete were the best.Thus,porous basalt can be used to prepare concretePorous basalt can replace other high-quality natural aggregate,which can effectively reduce the use of high-quality natural aggregate on the basis of ensuring the pavement performance,so as to achieve the purpose of environmental protection.However,due to the porous characteristics of its surface,its water stability has attracted much attention when it is used for road surface.In this paper,AC-20 asphalt mixture was designed,and the optimal asphalt content of the mixture was obtained by Marshall experiment,and the corresponding graded asphalt mixture was prepared.The water stability of the asphalt mixture was evaluated by the residual stability obtained by the immersion Marshall experiment and the splitting strength ratio obtained by the freeze-thaw splitting experiment.The smaller the aggregate particle size,the higher the sensitivity to water,and the easier it is to absorb water and lose water.The aggregate water content has a great influence on the stability of asphalt mixture,while the moisture will affect the adhesion between asphalt and aggregate,thus adversely affecting the stability of the mixture.The water stability of SBS modified asphalt mixture is better than that of No.70 petroleum asphalt mixture.In practical road construction,this experiment can be used for reference to prepare asphalt mixture,and provide a sufficient theoretical basis for improving the water stability of basalt asphalt mixture.In this paper,iron ore tailings（IOT）were separated from the tailings field and used to prepare cement stabilized macadam（CSM）with porous basalt aggregate.First,the basic properties of raw materials were studied.porous basalt was replaced by IOT with the ratios of 0,20%,40%,60%,80%,100%as fine aggregate to prepare CSM,and the effects of different cement dosage（4%,5%,6%）on CSM performance were also investigated.The mechanical and durability properties of CSM with the age of 7 d,28 d and 90 d were studied by the unconfined compression strength test,splitting tensile strength test,compressive modulus test and freeze-thaw test,respectively.The changes of Ca²⁺content in CSM with different age and different IOT ratio were analyzed by EDTA（Ethylene Diamine Tetraacetic Acid）titration method,and the micro-morphology of CSM with different age and different IOT replaced ratio was observed by SEM.It was found that with the same cement dosage,the strength of IOT-replaced CSM were weaker than that of porous basalt aggregate at early stage,and the strength reached the best at the replaced ratio of 60%.With the cement dosage of4%,the unconfined compressive strength of CSM without IOT was increased 6.78%from the age of 28 d to 90 d,while the splitting tensile strength increased 7.89%.However,once the IOT replaced ratio reached 100%,the value of that were increased about 76.24%and 17.78,which was better than 0%IOT.The CSM-IOT was better performed than the porous basalt CSM at age of 90 d.Therefore,IOT can replace porous basalt fine aggregate for pavement base.Figure[29]Table[18]Reference[115]...