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Although the adhered mortar content affects the properties of recycled aggregate concrete, there are few papers describing those effects. This paper presents the results of a series of experimental study on the effects of adhered mortar content on the quality of recycled coarse aggregate of concrete. 5 kinds recycled coarse aggregates made with heating and rubbing method, mechanical crashing method and separating lightweight particle with water stream method were tested for specific gravity, absorption and adhered mortar content. Specific gravity in oven-dried condition ranged from 2.35g/cm3 to 2.59 g/cm3, absorption ranged from 1.58% to 5.83% and adhered mortar content ranged from 8.0% to 68.4%, depending on manufacturing method of recycled aggregate. Absorption decreased linearly with the increase of specific gravity. Specific gravity decreased and absorption increased with the increase of adhered mortar content. Recycled aggregate made by heating and rubbing method showed lower adhered mortar content corresponding to lower absorption and higher specific gravity, while those made by mechanical crushing method showed higher adhered mortar content corresponding to higher absorption and lower specific gravity. In conclusion, the upper limit of adhered mortar content of recycled coarse aggregate is considered to be 15%, in order to keep up the quality of coarse aggregate and properties equal to natural coarse aggregate.

The effects of mix proportions on the properties of porous ecological concrete, and its coexistence with plants are discussed in this paper. In conclusion, the strength of porous ecological concrete is governed simultaneously by water cement ratio and cement content. Permeability is increased with any increment in aggregate gradation and any decrease in cement paste content. The thicknesses of concrete blocks and topsoil affect the growth of plants.

This paper presents the results of experimental study on the effects of adhered mortar content on strengths and durability of concrete. Compressive, tensile and shear strengths, modulus of elasticity, drying shrinkage and carbonation were tested on concrete mixtures with the water cement ratio of 0.43, 0.50 and 0.60 using 3 kinds recycled coarse aggregate and a riversand. The test results of concrete indicated higher compressive, tensile amd shear strengths and higher modulus of elasticity for concrete using recycled corase aggregate with lower adhered mortar content, lower absorption and higher specific gravity. Recycled aggregate with higher adhered mortar content also showed significunt adverse effects on drying shrinkage and carbonation. In conclusion, the upper limit of adhered mortar content of coarse recycled aggregate to keep up the quality of aggregate and concrete equal to natural coarse aggregate and those concrete is considered to be 15%.

Excellent mechanical properties combined with low density, good corrosion resistance and welding, make titanium alloy attractive structural materials for aerospace, ship navigation, weaponry and nuclear industry. However, the high cost impedes the further use of titanium alloy in different fields, and which is the key factor for productivity and further use of titanium alloy. Aiming at lost cost of titanium alloy, three parts of raw material, alloy design and working forming were overviewed, which will offer reference for how to low cost of titanium alloy.