Study On The Performance And Engineering Suitability Of Macroporous Ecological Concrete

The macropore ecological concrete has the advantages of fast forming,small pollution,low cost and good greening effect.Therefore,in the construction of "sponge city" which pays more attention to the ecological benefit,the popularization and application of the macropore ecological concrete are becoming more and more widespread,and are recognized by the people inside and outside the industry.However,in the actual engineering application of macroporous eco concrete,there are many problems such as too high p H value of plant environment and improper selection of plant species,which led to the fact that the ecological concrete can not play its proper greening role.Based on the application of macroporous ecological concrete in practical engineering,we manufactured kinds of macroporous ecological concrete through laboratory tests,which meets the requirements of compressive strength and porosity.Then we researched the effect of reducing alkali of silane soakag and silica fume admixture.After that,according to the plant growth characteristics,the most suitable plant combination for the slope engineering under different working conditions is selected and the greening effect is improved by increasing the germination rate.The following conclusions are obtained after analyzing and summarizing the data:(1)When the water-cement ratio is 0.35 and the ash-bone ratio is 1:8,the compressive strength and porosity of macroporous ecological concrete are the best,which are 5.6MPa and 35% respectively.Based on this,the grading improvement test of ecological concrete、the durability test of mineral admixture on ecological concrete and SEM test are carried out.When the water-cement ratio and ash bone ratio are unchanged,proper addition of fine aggregate will enhance the strength of eco concrete,which would not influence on porosity.When the sand ratio is 1:9,the compressive strength of concrete is 9.6MPa,the porosity is32%.The incorporation of silica fume can effectively enhance the strength and durability of eco concrete,but the workability will be greatly affected.The higher the dosage of silica fume,the worse the workability,and even the loss of fluidity.Therefore,the recommended dosage of silicon fume is 10%~20%.It can be used in combination with fly ash,which not only improves the strength of concrete,but also achieves the goal of improving workability.(2)Because the alkali reduction mechanism of silane soakag is different from the silicon powder mixing method,so commonly used basic measurement way "solid-liquid extraction" is unable to correctly measure the effects of alkali reduction,so we created a new way to measure alkali reduction effect of silane soakag.The results showed that the p H value of 7d was 12.41 and the p H value of 28 d was 12.86 using the traditional method to measure the plain ecological concrete.The silane soakag reduced the p H value of the plant environment to 8.91,and the effect of caustic soda is so significant that most plants can adapt to this basic strength.(3)Different plant combinations were put forward according to two common working conditions in China.The water level of the inland waterway slope is changed greatly,which require that plants grow both in soil and water for a short time,in addition,the growth of plants could not affect the speed and transport capacity of the channel.In this way,appropriate plants are that mainly herbaceous plants attached to the soil surface,such as bermudagrass,zoysiagrass,clover and alfalfa.The mountain slope protection not only maintains the stability of the slope,but also plays the role of beautiful landscaping,so it is recommended to form a combination of herbs,flowers and shrubs.Herbaceous plants such as calypcum,chrysanthemum and flower shrubs,such as gardenia,south tianbamboo,rose,peony,and triangular plum.(4)In this paper,the effect of slope protection and greening of the macropore ecological concrete is tested through practical engineering.The 28 d strength of the large pore ecological concrete after the completion of the paving is more than 5MPa,and it can give full play to the effect of slope protection.In the green effect,about 4 weeks after sowing,the green coverage rate of the slope has exceeded 95%.After 6 months,the plant roots have completely penetrated the concrete pores and rooted in the original soil layer,and the growth trend is excellent.