Use of the maturity method during highway bridge construction

During the construction of a highway bridge in New Jersey, researchers demonstrated the feasibility of using the maturity method to estimate in-place compressive strength of structural concrete elements. The conventional 28-day cylinder strength test did not closely represent the in-place concrete strength or include the effects of placement and curing operations, and a more rapid procedure was needed to proceed with critical construction operations. The maturity method was used only for three elements of the bridge structure (a column, a footing and a pier cap) to demonstrate the applicability of the technique to field crews. Procedures for determining maturity parameters, determining the datum temperature and establishing the strength-maturity relationship are given. Results indicate that overestimates of strength may occur if the maturity method is applied for in-place estimation of field strength without interpretation of the field maturity results based on statistical analysis of data.