Abstract:
Cement grouts are used in multiple applications including construction, maintenance, tunnels, piles and wells (oil, gas and water). With the wide spectrum of applications, there is a need to understand the changes in some of the critical properties with time since the cement continues to hydrate beyond 28 days of curing which has been highlighted in some of the recent studies. There is also very limited information on the long term properties of the cement grouts. Since the durability and quantification of the property changes with time are some of the important issues, in this study compressive stress-strain behavior and strength of cement grouts (Portland cement -Type 1) with and without 10% clay additive with the varying water-to-cement ratio (w/c) up to 1.0 was investigated for up to 4 years. Compressive stress-strain relationship highlighted the changes in the nonlinear behavior, modulus (initial, secant and tangent), failure strain and strength of the grouts. The addition of 10% clay also increased the compressive strength and the initial tangent modulus by over 80% and 90% respectively after 4 years (1460 days). Vipulanandan p-q stress-strain model was used to predict the stress-stain behavior of the grouts with the curing time. The constitutive model parameters were influenced by the three variables investigated w/c, curing time and clay content. Also a nonlinear model (NLM) was used to relate the model parameters to the three variables w/c, curing time and clay content.