| With the acceleration of urbanization, urban construction waste is increasing year by year, resources and environment have become increasingly prominent. Based on comprehensive utilization of construction waste, conserve resources, protect the environment, to promote the sustainable development of the construction industry, for semi-rigid recycled aggregate concrete can be more widely used materials recycled aggregate concrete and recycled aggregate concrete road blocks the semi-hard concrete of recycled aggregate preparation and molding process were studied in this paper.This paper introduces the construction waste, recycled aggregate, recycled aggregate concrete, recycled aggregate concrete and concrete semi-rigid molding process at first, and explained the environmental impact of construction waste, and the research development and situation of semi-hard concrete of recycled aggregate In China and foreign countries were introduced.Recycled aggregate used in the experiment from buildings demolition and renovation waste in Kunming. Recycled coarse aggregate with natural coarse aggregate to a comparative study in gradation, apparent density, bulk density, water absorption, crushing index, particle size distribution, porosity and so. Clay content, mud content, fineness, apparent density, bulk density, porosity, water content and water absorption properties of recycled fine aggregate were introduced. Function and physical performance of cement, fly ash, water reducing agent used in the experiment is simply explained and related devices used in Research Institute to be introduced.Mixture Ratio Design Method of Semi-rigid recycled aggregate concrete according to C30 of concrete as a benchmark and reference to mixture ratio design Method of dry concrete and road concrete. Co-binding experiments to determine the ratio of the final as: The amount of coarse aggregate per unit volume for the 1320 Kg/m3, fine aggregate per unit volume for the 600 Kg/m, water per unit volume for the 150Kg/m, cement per unit volume for the 350Kg/m3Workability, compressive strength and internal structure of semi-hard concrete of recycled aggregate have been studied from recycled aggregate replacement rate of 0%,30%, 50%,70% and 100%, Water-cement ratio of 0.3,0.4,0.43,0.5 and 0.6, Fly ash 0%,10%, 20%,30%and 40% of dosage amount of cement, and Water reducing agent 0%,0.2%, 0.3%,0.5%and 0.9%of dosage amount of cement four factors in the vibration molding conditions of frequency is 2860 beats/min, amplitude is 0.5mm and vibration time is 15s. When the consistency is 14s, water-cement ratio of 0.43, sand is 31.25%, fly ash is 20%, superplasticizer dosage is 0.3, the test of the prepared semi-rigid recycled aggregate concrete workability And the best compression performance,28d compressive strength value of up to 36.49 Mpa.Because molding process has a great influence on the compressive strength of Semi-hard concrete of recycled aggregate, so Molding process have been studied on the compressive strength of Semi-hard concrete of recycled aggregate from pressure molding, vibration molding and vibration pressure molding three factors with the mixture ratio of Water-cement ratio is 0.43, sand ratio is 31.25%,20%fly ash and 0.3% Water reducing agent of cement.Compressive strength value up to 39.54Mpa of Semi-rigid concrete of recycled aggregate with the factors of recycled coarse aggregate per unit volume for the 1320 Kg/m3, recycled fine aggregate per unit volume for the 600 Kg/m, water per unit volume for the 150Kg/m3, cement per unit volume for the 350Kg/m3, mixture ratio of Water-cement ratio is 0.43, sand ratio is 31.25%,20% fly ash and 0.3% Water reducing agent of cement, in the vibration pressure molding conditions of frequency is 2860 beats/ min, amplitude is 0.5mm and vibration time is 15s. So the semi-rigid concrete of recycled aggregate can be used to produce recycled aggregate concrete materials and recycled aggregate concrete road blocks which strength is less than 30Mpa. |
PDF Full Text Request