37º IAHS World Congress on Housing: - Universidad de Cantabria

XXXVII <strong>IAHS</strong><strong>World</strong> <strong>Congress</strong> on HousingOctober 26 – 29, 2010, Santander, SpainCODE: 938A PROCEDURE TO ASSESS BUILDING STRUCTURALSAFETY BASED ON CONCRETE MATURITY METHODC. Vázquez-Herrero, I. Martínez-Lage, J. Eiras-López, G. Vázquez-HerreroDepartment of Construction TechnologyUniversity of La Coruñae-mail: cvazquezh@udc.esKey words: concrete maturity method, building, monitoring, nondestructive testingAbstractThe reduction of deadlines in building construction implies loading structures at early stages:mould and formwork removal, shoring, shoring-reshoring, transfer of prestress to concrete,among others, are carried out a few hours or days after concrete casting in slabs. To ensurethat structural safety requirements are met it is necessary to check that concrete has gotsufficient strength.Testing standard concrete specimens, although these are conserved “in situ” until their testingdoes not take into account the real thermal conditions in the structure, which are stronglyinfluenced by the element thickness, the type of formwork, the curing system, etc.Consequently this experimental technique is not representative to determine the mechanicalproperties of concrete at early ages (Malhotra, 2004).Concrete maturity method estimates accurately concrete strength at early age. This techniqueis based on registering the temperature history of a structure made from a previouslycalibrated concrete mix, and has been applied successfully to many structures worldwide.A research program has been developed in order to adapt the concrete maturity method to theSpanish concrete standard EHE-08. As a result a new procedure to estimate concrete maturityon the safe side has been developed. Also technical criteria to set appropriate deadlines forbuilding critical operations have been established: mould and formwork removal, shoring,shoring-reshoring, transfer of prestress to concrete, etc.37º <strong>IAHS</strong> <strong>World</strong> <strong>Congress</strong> On Housing Science 311