Abstract
This study examined the effectiveness of zeolite addition to reduce the autogenous shrinkage of high-performance cement-based concrete (HPC). The zeolites were replaced up to 15% of the cement content by weight and their mean particle size varied from 5.6 to 16.7 µm. To evaluate the crack resistance of HPC containing zeolites, the ring tests and internal relative humidity measurements were performed at different ages. The compressive strengths were determined at 3, 7, 28 and 90 days of curing. Test results confirmed that the addition of zeolite was promising and favourable in enhancing the compressive strength, crack resistance and reducing the autogenous shrinkage of HPC due to synergistic pozzolanic and internal curing effects. The autogenous shrinkage tended to decrease with the increase in zeolite content and its particle size. In addition, the extent of the autogenous shrinkage development at the early ages decreased with higher zeolite content replaced. Furthermore, to predict the autogenous shrinkage of HPC containing zeolite, an improved model has been proposed, in which the conventional ultimate autogenous shrinkage strain and time function were modified by introducing new parameters accounting for the zeolite content and its particle size. It appeared that the proposed model was able to capture the autogenous shrinkage behaviour of HPC with or without zeolite, while the fib 2010 model underestimated the autogenous shrinkage of HPC containing less than 10% zeolite replacement.
Highlights
High-performance cement-based concretes (HPC), such as high-performance concrete and ultra-high-performance concrete, have been considered as promising materials in the last decade because of their advanced characteristics in the compressive and tensile strength, stiffness and long-term durability compared to the normal or high-strength concretes
This study intensively examined the effects of zeolite addition on the shrinkage of HPC
The effects of zeolites on the autogenous shrinkage of high-performance cement-based concrete were evaluated on various HPC mixtures containing up to 15% zeolite replacement of cement with three mean zeolite particle sizes of 5.6, 10.3 and 16.7 μm
Summary
High-performance cement-based concretes (HPC), such as high-performance concrete and ultra-high-performance concrete, have been considered as promising materials in the last decade because of their advanced characteristics in the compressive and tensile strength, stiffness and long-term durability compared to the normal or high-strength concretes. Such concretes typically have low water-to-binder (w/b) ratio and high binder content, including cement and mineral admixtures, which results in a high compressive strength, high elastic modulus and excellent durability. The risk of cracking induced by the restrained autogenous shrinkage would limit the application of HPC in construction. HPC offers an extremely dense matrix, Materials 2020, 13, 3773; doi:10.3390/ma13173773 www.mdpi.com/journal/materials
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have