An Experimental Study On Properties Of The Permeable Concrete

Permeable concrete are important materials for the construction of "sponge city" in China.In this thesis,the main contents of the research are as follows(1)A reciprocal relationship between the strength and water permeability of permeable concrete.This thesis deeply studies the above two kinds of performance.It selects the sand ratio,water cement ratio,design strengthening agent content and porosity as the four facors of the orthogonal test,and different proportion are selected as of four levels.By the test of compressive strength,flexural strength,permeable coefficient and porosity through the 16 groups of mix molding test block as well as the analysis of the test results of the range,variance and efficacy coefficient,it concludes the main factors affecting the permeable concrete performance and the secondary factors,and finally chooses a set of mixture ratio,establishes the relationship among the permeable coefficient,strength and the other factors.(2)By using the orthogonal experiment,the mixture ratio is optimized.The research studies the two kinds of forming method(vibration molding,static pressure molding)that affects the performance of of permeable concrete study.The study compares five kinds of vibration time including 6 s,10 s,14 s,18 s and 22 s as well as five different molding pressure including 20 KN,40KN,60 KN,80KN and 100 KN.Through the test of performance of test block,it finally concludes optimal forming time of vibration molding as well as the optimal molding pressure of static pressure molding.(3)By using the orthogonal experiment,the mixture ratio is optimized.The researchcarries out an aggregate analysis on the particle size that influences the properties of permeable concrete(mainly for the Guami stone and coarse sand).By testing the compressive strength,flexural strength and permeable coefficient,the optimal particle size of permeable concrete properties is concluded.(4)Of the Guami stone and coarse sand in different aggregate of permeable concrete,mixed them with 5%,7%,9% and 11% respectively of slag,silica fume,fly ash and latex powder,under different freeze-thaw cycles,its quality loss and loss of strength and failure mechanism are analyzed.Also,the best less permeable concrete freeze-thaw damage type and dosage of admixture are optimized.(5)Of the two kinds of aggregate of permeable concrete of Guami stone and coarse sand,they are soaked in the three concentrations of sulfate of 3%,5% and 7%.And by 30 times,60 times,90 times,120 times of the dry-wet circulation system of erosion and 3 months,6 months,9 months,12 months long-term immersion system,the apparent changes of concrete are observed.Its quality of corrosion resistant coefficient,strength,corrosion resistant coefficient are tested.The research also analyzes the reasons of the gradually damage from the inside out of permeable concrete under sulfate erosion.(6)By using the Monte Carlo Method,permeable concrete aggregate,interface and porosity model are set up.And numerical simulation of permeable concrete compressive damage is carried out through the finite element software.It also analyzes its internal damage and the reason of cracking and regularity of aggregate under the compression state.