Evaluation of strengthening through stress relaxation testing of organo-modified montmorillonite reinforced cement mortars

► Static compression and stress relaxation tests on organo-modified montmorillonite (OMMT) reinforced cement mortars under different temperatures and imposed strains were conducted. ► The test results, including pore size distributions and activation energies, reinforces the positive effects observed on the initial elastic modulus, compressive strength and strain exponent of cement mortars. ► Furthermore, the adequate dosage of OMMT to give a higher stiffness and strength of cement mortar is proposed.