Impact and frost damage resistance of 3D printed concrete

Abstract

3D concrete printing technology is the future technology in service to the world and environment. The high-performance concrete used in the 3D concrete printing technology requires a special mix during its fresh state. In addition, the evolution of this technology is widening the implementation of more by-products from different industries and chemical admixtures in the mix design. However, there are still a lot of skepticism concerning the durability of 3D concrete printed structures such as its performance that adversely affects its implementation in the construction field. In this regard, investigating the durability performance of 3D concrete printed structures is vital. This study is aimed at evaluating the durability performance against falling weight impacts and frost damage of printed mortar by comparing printed and casted samples. Therefore, two different mixes constituting of 10% silica fume substitution by weight of the binder with varying water to binder ratio, 0.4 and 0.36 respectively, but same workability due to superplasticizer modification in either printed and casted mortars were prepared. The impact resistance of cylindrical samples after 28 days of curing in water is examined in a drop weight impact test. Moreover, the effect of 90 cycles of freezing and thawing after 28 days of curing in water is studied by testing the mechanical performance and weight loss of the samples. It was found that the process of printing does not affect the impact neither the freezing and thawing resistance. In addition, the samples’ weight loss after 90 cycles of freezing and thawing confirmed the results related to the mechanical performance. However, the results of this study shows that the effect of water to binder ratio on the freezing and thawing resistance is not similar to the effect of water to binder ratio on the impact resistance in both printed and casted samples.