This document reviews different maturity methods used to predict the compressive strength of concrete based on its temperature history. It discusses two main maturity models - the Nurse-Saul function and the Arrhenius function. The Nurse-Saul function calculates maturity as the sum of time multiplied by temperature above a datum temperature (usually -10°C). The Arrhenius function is based on the concept of activation energy from chemistry and calculates maturity as an integral of time and temperature. The document also reviews past literature on maturity methods and discusses how maturity can be used to estimate in-place concrete strength for purposes like formwork removal or post-tensioning schedules.