Preparation Technology Of High Strength Concrete With High Volume Cementitious Materials

High-yield,high pollution and low utilization industrial waste such as low-grade fly ash,slag,red mud and shortage of cement resources are the world's problems.In order to solve these two problems,the high use of industrial waste in the preparation of concrete become a hot spot for research.However,the strength of concrete prepared under the condition of high volume cementitious materials is very low,which restricts its application in engineering.This paper uses a combination of microanalysis and experimental research,comprehensive use of ultrafine cement,mixed material activity excitation,mix optimization and autoclave curing means,prepared out high volume of cementitious material(equivalent to 70% of cement),high strength(120MPa or more)concrete.Comprehensive performances of fly ash,red mud and slag are researched and analysised through X-ray diffraction microscopic test method,which is the theoretical basis for industrial waste used as ultrafine cement admixture.The effects of the strength of the cement clinker particles and the robustness of the mixed materials on the compressive strength of the concrete were studied by grinding the cement clinker in different degrees and comparing the compressive strength of the mortar with different solidified materials.The results show that the cemented to ultrafine cement can be refilled in the granules of the mixture so that the cohesive force between the particles increases and the strength of the specimen is increased.The contribution of the mixture to the compressive strength of the specimen is the result of its activity and ruggedness.Through the physical and chemical means to stimulate the activity of the mixture,to achieve high volume of cementitious material ultrafine cement strength.The results show that the grinding strength of fly ash has a great influence on the compressive strength of the cement mortar specimen.With the increase of the specific surface area of the fly ash,the compressive strength of the mortar is improved.Under the conditions of the use of conventional salt and alkali activator is different from the use of acid can also be used to stimulate the activity of the mixture.The strength of concrete with high volume of cementitious material was further improved by means of steaming.The results show that choosing the initial strength of the specimen and the temperature and time of the autoclave curing can make thecompressive strength of the specimen greater than the compressive strength of 28 days,it can solve the problem of strength loss caused by steaming.Lime water bath curing can solve the problem of specimen water loss,there are good to improve the strength effect.Through the use of intermediate aggregate and nickel iron sand,prepare out high strength mortar specimens,on the basis of the study of the impact of concrete compressive strength factors.The results show that the addition of the intermediate aggregate between the cementitious material and the nickel iron sand can greatly improve the strength of the specimen.comprehensive use of ultrafine cement,mixed material activity excitation,mix optimization and autoclave curing means,prepared out compressive strength of 120 MPa concrete with 70% volume of cementitious material.