Experimental investigations on early crack development in fully restrained reinforced concrete members with active zero-displacement control

Abstract The development of restraint-induced stress in reinforced concrete members at an early age can be tested using setups applying either passive or active displacement control. To provide results relevant for the practical design minimum reinforcement to limit crack width, actively controlled test setup large specimens was developed perform a systematic experimental campaign focusing on under well-defined mechanical and thermal boundary conditions. full degree restraint achieved by preventing any member allowed theoretical interpretation evolution, deformation behaviour cracked uncracked regions, variety parameters, including hydration rates, height, bar diameters subsequently ratio. cracking process, starting with primary cracks accompanied secondary within effective area, is monitored combination tensile strength Young’s modulus concrete. Furthermore, time forces released upon occurrence, considering effect self-equilibrating stresses, are determined, analysed, compared crack-force based rules determine amount that ensures width limitation.