The Impact Of Grinding Aid On The Performance Of Composite Portland Cement

With the rapid development of our economy, cement production is also graduallyincreasing, cement is a high energy consuming industry, energy saving and emissionreduction mission are critical. Cement grinding is the biggest link energy consumption inthe production process, in cement grinding process in the incorporation of grinding agent,not only to improve the grinding efficiency, but also can improve the performance ofcement, reduce energy consumption, cement grinding agent to help research hasconsiderable economic value and social benefits, have important significance to energysaving and emission reduction. Limestone is a kind of easily available and cheap materials,such as not to use not only occupies the site piled up, also can cause the pollution to theenvironment. As mixed materials production of composite Portland cement with limestonepowder, instead of increasing shortage of fly ash and the relatively high price of slag, tosolve the shortage of raw materials, the actual production is important to reduce theproduction cost of raw materials, energy saving and emission reduction. This thesis mainlystudies the influence of limestone powder on the composite cement, grinding aids on thecomposite cement performance influence and optimization of mixture ratio, concreteadmixtures on mixed grinding agent composite cement adaptability research, grinding aidson the durability of the cement. The research contents are as follows:First of all, the choice of commonly used P·C32.5ratio, clinker and gypsum dosagemethods used with fixed cement, limestone powder instead of slag, fly ash compositecement, study the influence of limestone powder on the properties of cement.Secondly, has studied seven kinds of monomer grinding aids grinding effect ofcomposite Portland cement comprehensive performance and help in different dosage effect.The results show that, the monomer grinding aids have a good grinding effect, does notaffect the condition of normal consistency of cement content, setting time, enhance thefunction of cement mortar strength, increasing the cement hydration heat of cement hydration rate, improve. Using the orthogonal test was optimized composite grinding aids,and selected3groups of better performance of composite auxiliary grinding agent ratio.Third, study on Adaptability of concrete admixture doped composite cement grindingagent and grinding agent effect on the durability of cement. The results show that,Naphthalene water reducing agent to help the poor adaptability of admixture cementgrinding agent, Polycarboxylate Superplasticizer, early strength agent, retarder for cementgrinding agent mixed with good adaptability. The Composite grinding aids to theincorporation of sulfate resistance, frost resistance, carbonation resistance of cementincreases, but increasing the cement mortar contraction.Finally, by using SEM, XRD instruments, the mixed grinding agent composite cementand composite cement with micro test blank sample. By SEM, the incorporation ofgrinding aid agent of cement paste has more amorphous C-S-H gel, gap mesh, needle-like,rod material filling cement product, the porosity of cement paste decreases, more compact.By the analysis of XRD spectra, the incorporation of grinding aid agent of cementhydration products of Ca (OH)2, AFt increased, Not hydrated particles decreased, thehydration rate of speed, performance at increasing the strength of cement mortar strength.