Experimental Study on Additives for the Reduction of Alkalinity for Ecological Concrete

Concrete has been one of the most widely used materials in Engineering, which also induced the problems of vegetation destruction, soil erosion, and even deterioration for ecosystems. The ecological concrete was proposed to reinforce the slope due to its characteristics of high strength and large porosity to ensure the growth of plants. However the high alkalinity for ordinary portland cement constrained the growth of plants. An experimental test including 15 groups of samples was carried out to evaluate the effects of materials including polycarboxylate superplasticizer, calcium carbonate, ammonium bicarbonate, potassium dihydrogen phosphate, silica fume, ferrous sulfate and calcium lignosulfonate on pH value for ecological concrete. Under the condition that the compressive strength and porosity meet the requirement of ecological concrete, two sets of additives were proposed, which are suitable for the slope with high strength and the slope with low alkalinity requirements respectively.