The twist-core method is a technique for estimating in-place concrete strength. A preliminary study on the failure torque determined by this method and standard compressive strength for different strengths and two types of coarse aggregate was carried out. The results show that the equipment used was appropriate for producing quick results. A good torque-compressive strength correlation was observed. A theoretical torque-strength prediction model is presented and was observed as being unreliable for predicting concrete strength. Thus an experimental correlation is needed for specific materials. It was observed that torque-resistance is influenced by the type of aggregate used. The method could potentially be used for estimating in-place concrete strength.
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