Experimental Study Of The Preparation Of Ecological Concrete Using Waste Fly Ash

With the development of China's power industry, the total generating capacity is nearly700million kw,among them, Coal-fired power generation accounts for about80percent, the annual emission of fly ash is nearly300million tons, If not be used, they will not only give the environment a huge burden, but also cause a serious waste of resources. There are two gray fields in the Shandong province's zoucheng power plant, the storage of waste fly ash is about300million tons, If this part of the waste fly ash is utilized, it will bring substantial environmental and economic benefits. This article is a study of waste fly ash in the application of ecological concrete.Waste fly ash is too rough, can not be directly applied, which need grinding. Firstly, the paper use orthogonal experiment to consider the water content, grinding time, grinding aid dosage of three factors, grinding the waste fly ash into II fly ash which is qualified in the fineness,water demand,loss on ignition and SO3content of the four indicators. In this paper, we use the30%content of fly ash, also use aliphatic and polycarboxylate two superplasticizer, to study the workability of the paste, mortar and concrete. due to the use of aliphatic superplasticizer, Fluidity loss is too large, thus this study maintain the fluidity of the way.This paper studies the concrete strength mixing the30%content and60%content of fly ash, the strength of concrete mixing the30%content of fly ash could meet the construction requirements, and the60%of the dosage strength is too low, which need to add chemical activator to stimulate the early strength of fly ash, through the single doped sulfate and alkaline salts, complex mixed experiments, we compound into high-performance concrete activator. The article also examined the strength of concrete after mixing the mineral powder and super absorbent (SAP), The final mix ratio is able to meet the construction requirements. When adding into tly ash, slag, and SAP. the crack resistance of concrete is significantly changed to better, The article studied and analyzed the details through the tablet experiment.By XRD, SEM and other modern objects detection means, the paper studied the activator on the excitation mechanism of high volume fly ash and slag, also studied the impact of SAP on the cement and mineral admixture,which revealed the intrinsic link between microscopic structure and macroscopic properties. The activator makes the concrete pore structure of the early hydration products improved, the paste is more dense, thus the early strength is got increased, the SAP makes the increase in crystal content of the concrete at early and late, the proportion of the C-S-H gel is increased, the concrete density increases, and thus the strength improved.The paper is based on the gravel filling model of the concrete, put forward three factors influencing the concrete strength, that is, pebble strength, hardened paste strength and the adhesive junction strength of paste and aggregate, Digital formula gives the calculation method of the activity index and volume filling rate of mineral admixture, put forward cementitious material to the overall standard thick water consumption and1-hour water absorption concept, and total mixing water is divided into two parts of the cementitious material as a whole standard thick water and aggregate moist water, finally proposed mix proportion of concrete scientific calculations, also made an attempt to change the concrete semi-computing design current situation based on the experience.Finally, the article studied the extensive use of fly ash in particular waste fly ash from ecological concrete's ecological benefits, social benefits and economic benefits.