Factors affecting the results of concrete compression testing: A review

Abstract Concrete compression is complex. Yet, understanding this behavior is indispensable for design. There are three main factors that affect concrete compression results: the specimen size, shape, and friction at its ends. These factors affect the observed phenomena, and they affect each other. This paper aims to review the current knowledge on concrete compression and the effect of size, shape and friction on it. Understanding their effects is essential for a safer design and more effective testing. Most of the advancements in this topic is old, with a few exceptions. So, this review highlights the gaps in knowledge, and reintroduces them once again. Concrete design codes should consider the size effect in calculations. Reducing friction is recommended to lower the strength variation. Reduced friction may also be used for testing smaller specimens more reliably. This leads to more accurate, and more economic concrete testing.