Abstract
This study selected water-cement ratio 0.5 and slump 16 cm for ACI mix design, and used nano- clay to replace 0.1%, 0.3% and 0.5% of cement by weight to make cylinder and angle column specimens. The effects of different high temperatures on the compressive strength and heat transfer coefficient were tested, and the ignition loss of nano-clay cement paste was measured. The results showed that an appropriate replacement of nano-clay for 0.3% - 0.5% of cement can enhance the strength and heat transfer coefficient of concrete, especially 0.3% replacement. The 0.1% nano- clay replacement for cement reduces the strength and heat transfer coefficient of concrete. When the ambient temperature exceeds 300?C, the nano-clay concrete strength begins to decline, and the heat transfer coefficient decreases greatly, the effect of hot environment on the strength trend of nano-clay concrete is similar to that on normal concrete. When the nano-clay replaces cement by 0% - 0.5%, the ignition loss is approximately in exponential and logarithmic relationships to the compressive strength respectively when the ignition loss is smaller than and greater than 6%.
Highlights
When the dimensions of materials enter into the nano range, conventional theories of material science no longer hold true
For normal concrete (W5N0), the concrete strength increases with the curing age, the compressive strength on Day 28 is 33.7 MPa, the strength on Days 7 and 14 is 73.6%
For normal concrete (W5N0), there is a delay of one hour at 25 ̊C and 300 ̊C, the strength is increased by 13.4% and 9.5% respectively compared with the strength on curing Day 28
Summary
When the dimensions of materials enter into the nano range, conventional theories of material science no longer hold true. Cement paste’s main source of strength comes from C-S-H gel and CH crystals, which interact with each other chemically when heated. (2016) Effect of Hot Environment on Strength and Heat Transfer Coefficient of Nano-Clay Concrete Paper Title. This study simulates the concrete under the effect of fire to research the effect of nano-clay on the compressive strength and heat transfer coefficient of concrete. The feasibility of using the ignition loss test result to evaluate the retained strength of concrete is analyzed
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have