The Environmental Coordination Assessment Of Naphthalene Based And Polycarboxylic Acid Superplasticizer

Environmental Coordination Assessment,also known as Life Cycle Assessment(LCA),is the compilation and evaluation of the input,output and potential environmental impact in the life cycle of a product system.The application of LCA in industry will guide and promote the greening of materials and the sustainable development of industry.Concrete admixture is one of the indispensable components of modern concrete and is an important method and technology of concrete modification.Adopted the international general Recipe method system to evaluate naphthalene series and poly carboxylic acid series superplasticizers superplasticizer of environmental load,the eight types of environmental impact in the impact assessment have been determinated: climate change(GWP),human toxicity(HTP),photochemical oxide formation(POFP),particulate form(PMFP),land acidification(AP),oceanic eutrophication(MEP),metal resource depletion(MDP)and the depletion of fossil resources(FDP).By evaluating the environmental coordination of naphthalene superplasticizer,polyether superplasticizer and polyester superplasticizer,the processes in the life cycle of three kinds of superplasticizer and the total environmental load were obtained.The main influencing process of naphthalene series superplasticizer is the production process of auxiliary materials.The environmental impact of this process accounts for 58.0% of the total environmental impact of the whole life cycle.The main environmental load of naphthalene superplasticizer is particulate matter formation,followed by ocean eutrophication and land acidification,which respectively account for 30.5%,15.5% and 14.6% of the total environmental effect.The main influencing process of polyether superplasticizer is the production process of large monomer,whose environmental impact accounts for 82.6% of the whole life cycle.The main environmental loads of polyether superplasticizers were fossil resource depletion,followed by human toxicity and photochemical oxide formation,accounting for 29.6%,18.2% and 15.7% of the total environmental effects,respectively.The main influencing process of polyester superplasticizer is also the production process of large monomer.The main environmental loads of polyester superplasticizers were fossil resource depletion,human toxicity and particulate substance formation,accounting for 29.5%,18.7% and 17.7% of the total environmental effects,respectively.Under the same water reduction rate,each environmental load of naphthalene superplasticizer is higher than that of polycarboxylic acid superplasticizer,in which the formation of particulate matters is the most prominent type of environmental load,and naphthalene superplasticizer is 8.4 times that of polycarboxylic acid superplasticizer.The total environmental impact load of the naphthalene superplasticizer is 3.1 times that of the polycarboxylic acid superplasticizer.Therefore,it can be said that polycarboxylic acid superplasticizer resource consumption is low,pollution emission is low,it is the green environmental protection superplasticizer.Under the condition of maintaining the same strength,the environmental impact of concrete could be substantially reduced by using polycarboxylic acid superplasticizer and saving cement.In the type of C30 grade concrete,the particulate substance could be reduced by 150 times through applying superplasticizer compared with the reference,and other influence types are also significantly lowered.The addition of polycarboxylic acid superplasticizer accounts for 0.2 % of the environmental impact of C30 grade concrete.Adding additives can save 125 kg of cement,and saved cement accounts for 7.1 % of the environmental impact of C30 grade concrete.In the type of C60 grade high strength concrete,the particulate substance could be reduced by 121 times through applying superplasticizer compared with the reference,and other influence types are also significantly lowered.The addition of polycarboxylic acid superplasticizer accounts for 0.3 % of the environmental impact of C60 grade concrete.After adding additives,196 kg of cement can be saved,and the saved cement accounts for 10.1 % of the environmental impact of C60 grade concrete.