The Influence Of Differert Super Plasticizer In Mineral Admixture On Concrete Strength And Durability

Concrete as a structural material, compression strength is the main performance. frost resistance of concrete is a focus of attention of the academic community in general in cold areas or coastal cities, to which domestic and foreign scholars have done a lot of useful exploration.Modern concrete which construction requirements should have a certain level of intensity and and frost resistance, both of them are affected by the pore structure of concrete, even the internal pore structure of concrete is the decisive factor of its performance,so the pore structure which after cyclic freezing-and-thawing effect in cold a rea and the strength of concrete that studied in this paper have theoretical significance and engineering value. Concrete water-reducer is a important additives in the concrete, in this paper,compared the the second generation of naphthalene and the third generation of poly carboxylic-acid.The concrete were incorporated into the mineral admixtures and grouped test, the microstructure and hydration products of specimen condition are analyzed.Research is divided into three stages:First of all, according the trial objective and micro-structure analysis to determine the mix proportion of concrete, the samples divided into three groups for blank groups, naphthalene and poly-carboxylic acid group. The samples will be maintained on concrete curing standards.In the second place, compression testing in line with GB/T 50081-2002 "standard for test methods of mechanical performance of ordinary concrete", using pressure testing machine to preloaded specimens and uniform loading continuously, and test strength of concrete specimens which age were 7d, 28 d, 56 d.The sample of the test age for 28 days through mercury test.The rusults are:fly-ash reduces the porosity of concrete,and makes the most probable aperture is slightly higher. The above results show that the slag powder on the porosity of the specimen have certain adjustment. Mixed use of slag powder and fly ash make cement stone a tendency to significantly reduce the wool stoma.Last but not the least, test according to the frost resistance test "fast freeze law" which from GB /T50082-2009 "standard for test methods of longterm performance and durability of ordinary concrete", and use relative dynamic elastic modulus andweight change of concrete as the evaluation index.The results of the analysis is : Air-entraining agent make inside the concrete has enough air content, affect the pore structure of concrete, the frost resistance durability of concrete was optimized. Mixed with fly ash can reduce the mass loss. Slag powder and fly ash mixed with relative dynamic elastic modulus of the sample, but can not effectively reduce quality loss rate...