Title:
Impact Resistance and Strength of SCC Containing Crumb and Powder Rubbers
Author(s):
Assem A. A. Hassan
Publication:
Symposium Paper
Volume:
347
Issue:
Appears on pages(s):
215-229
Keywords:
Impact strength; SCC; compressive strength; crumb rubber; powder rubber
DOI:
10.14359/51732666
Date:
3/1/2021
Abstract:
The inclusion of rubber in concrete mixtures improved the impact resistance but negatively affected the
strength and fresh properties of self-consolidating concrete (SCC). The objective of this investigation was to optimize
the balance between the improved impact resistance and the reductions in the strength and fresh properties of
rubberized SCC mixtures. This investigation evaluated and assessed the type/size and percentage of rubber needed to
develop successful SCC mixtures with maximized impact strength and minimized reductions in strength. The studied
variables were the type/size of rubber used (crumb rubber (CR) and two sizes of powder rubbers), percentage of rubber
(0%, 15%, 25%, 30%, 35%, and 40%), type of concrete (SCC and vibrated concrete), and the use of fibers in the
mixture. Because of the fresh properties restrictions of SCC, it was only possible to develop rubberized SCC with up
to 25%, 30%, and 35% CR, powder rubber 40/80, and powder rubber 140, respectively. With the absence of fresh
properties restrictions of SCC, it was possible to develop vibrated rubberized concrete with up to 40% of any type of
rubber. Using higher percentages of rubber in vibrated rubberized concrete dropped the compressive strength to less
than 25 MPa (3.63 ksi). The results also indicated that despite the slight improvement in the fresh properties and
strength of mixtures with powder rubbers compared to mixtures with CR, mixtures with CR showed significantly
higher improvements in the impact resistance.