Experimental study on recycled steel fiber concrete
Some basic properties of recycled steel fiber aggregate were tested, such as surface features, water absorption, apparent ensity, crushing index, cube compressive strength and so on. Recycled steel fiber aggregate were used to replace the natural aggregate by 0%, 25%, 50% and 100% proportion to make concrete. Afterward, compressive strength, splitting tensile strength and flexural strength were investigated at ages 3, 7 and 28 days. The results showed that thorn appearance of recycled steel fiber aggregate makes packing density decrease, crushing value and absorption increase. The compressive strength, splitting tensile strength and flexural strength of the recycled concrete depend on the mix proportions. Generally, the strength of recycled concrete can be 15–25% lower than that of concrete made with virgin aggregate.
A Comprehensive Review on the Utilization of Recycled Waste Fibers in Cement-Based Composites
Ecological problems such as natural resource depletion and massive quantities of waste for disposal are now guiding progressive civilization towards sustainable construction. The reduction of natural resources and the discarding of debris into open landfills are the two main environmental concerns. As a result, managing these solid wastes is a major challenge worldwide. In comparison to disposal, insufficient landfills, ecological degradation and the economic load on the relevant agencies, recycling and reusing waste materials have a considerable influence. Waste fiber has been studied for use as a cement-based composite (CBC) ingredient. Recycling waste fibers not only makes the cement composite more cost-effective and long-lasting but also helps to reduce pollution. Plastics, carpets and steels are among the various types of waste fibers reviewed in this study for their applications in cement-based materials. The mechanical properties of CBCs with different kinds of recycled-waste fibers were explored, including their compressive, flexural and splitting tensile strength and durability properties. The use of recycled fibers in the construction industry can help to ensure sustainability from environmental, economic and social standpoints. As a result, additional scientific research is needed, as well as guidance for more researchers and experts in the construction sector to examine the unknown sustainability paths. The barriers to the effective implementation of waste fiber recycling techniques in the construction sector were reviewed, and various solutions were proposed to stimulate and ensure their use in CBCs. It was concluded that CBCs containing recycled fibers provide a long-term and cost-effective alternative for dealing with waste materials.
Experimental study on freeze-thaw durability of recycled concrete
It is an laboratory investigation on the resistance of freezing and thawing of recycled aggregate concrete(RAC).The 50-year-old recycled coarse aggregate were used in the RAC,using the replacement percent of 0%,25%,50%,75% and 100%.It is found that the standard of the durability of freezing and thawing was satisfied,and the RAC can be used in the normal projects.