The porous aggregate pre-soaking in relation to the freeze–thaw resistance of lightweight aggregate concrete

2012 ◽  
Vol 30 ◽  
pp. 761-766 ◽  
Author(s):  
B. Kucharczyková ◽  
Z. Keršner ◽  
O. Pospíchal ◽  
P. Misák ◽  
P. Daněk ◽  
...  
Keyword(s):  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Freeze Thaw

Experimental Study on Freeze-Thaw Damage Mechanism of Lightweight Aggregate Concrete

2010 ◽  
Vol 7 (1) ◽  
pp. 102450
Author(s):  
S. W. Dean ◽  
Jize Mao ◽  
Koichi Ayuta ◽  
Hui Qi ◽  
Zongmin Liu
Keyword(s):  
Experimental Study ◽  
Lightweight Aggregate ◽  
Damage Mechanism ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Freeze Thaw

Analysis of Freeze-Thaw Damage of Lightweight Aggregate Concrete

2009 ◽  
Vol 417-418 ◽  
pp. 829-832
Author(s):  
Ji Ze Mao ◽  
Koichi Ayuta ◽  
Hui Qi ◽  
Zong Min Liu
Keyword(s):  
Water Content ◽  
Coarse Aggregate ◽  
Lightweight Aggregate ◽  
Frost Damage ◽  
Lightweight Aggregate Concrete ◽  
Freezing And Thawing ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Expansion Pressure ◽  
Micro Cracks

Since lightweight aggregate usually accounts for a higher percentage of the concrete by volume, the properties of lightweight aggregate can significantly influence the properties of the resulting concrete. In this study, we investigated the effects of the water content of lightweight coarse aggregate (LCA) on freeze-thaw resistance of lightweight aggregate concrete (LC) and analyzed how to control the fatal frost damage - cracks in LC. The results showed that the freeze-thaw resistance of LC was determined by the water content of LCA. It is clear that lowering the water content of LCA below 17% is the key method to secure the freeze-thaw resistance of LC. The study showed that the higher the water content of LCA, the higher the weight loss and the larger pore volume of LCA, the bigger the length expansion and the lower the durability factors of LC after freezing and thawing. Internal cracks occurred only in the concrete specimens that contained LCAs with higher water content when subjected to freezing and thawing. Expansion pressure occurred easily in the higher water content LCAs and micro-cracks formed initially in the weak grains. Then micro-cracks enlarged and spread to the mortar as the number of freeze-thaw cycles increased. This process eventually caused LC expansion and damage.

Experiment on the Mechanical Performance of Fiber Lightweight Aggregate Concrete after Freeze-Thaw and Elevated Temperature

2014 ◽  
Vol 919-921 ◽  
pp. 1790-1793 ◽  
Author(s):  
Bo Cheng ◽  
Jing Huang ◽  
Wen Ting Jiang ◽  
Jian Min Wang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Lightweight Aggregate ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Polyacrylonitrile Fiber ◽  
Aggregate Concrete ◽  
Freeze Thaw

Experiment on the compressive strength and splitting tensile strength of fiber lightweight aggregate concrete (FLWAC) after freeze-thaw cycling and high temperature was tested through blending polyvinyl alcohol fiber (PVAF) and polyacrylonitrile fiber (PANF) in aggregate concrete respectively. Five temperature levels, room temperature, 200°C, 400°C, 600°Cand 800°C were selected to heat the FLWAC test blocks after 25 times of freeze-thaw cycling. The micro-structure of FLWAC was observed through SEM. The experiment results show that, the cubic compressive strength of FLWAC is improved when the temperature is above 200°C, and the splitting tensile strength of FLWAC is obviously improved between the ranges from room temperature to 600°C. Blending fiber can weaken the brittle fracture performance of LWAC after freeze-thaw cycling at the peak loading state. However, the mass loss doesn’t have obvious improvement before and after 25 number of freeze-thaw cycling.

Correlation Analysis of Evaluation Indexes for Freeze-Thaw Damage of Lightweight Aggregate Concrete

2010 ◽  
Vol 452-453 ◽  
pp. 657-660
Author(s):  
Ji Ze Mao ◽  
Zong Min Liu ◽  
Koichi Ayuta ◽  
Wan Jie Yin
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Aggregate Concrete ◽  
Evaluation Indexes ◽  
Freeze Thaw ◽  
Dynamic Modulus Of Elasticity

Freeze-thaw damage is one of the most representative damages in concrete durability. In this study, rapid freezing and thawing tests were conducted to investigate the freeze-thaw resistance and analyze the correlation of the evaluation indexes of lightweight aggregate concrete with different water-cement ratios. The high correlation was confirmed between the length change and relative dynamic modulus of elasticity of lightweight aggregate concrete. The relative dynamic modulus of elasticity decreased with the increase of concrete length. However, the correlation was different according to the water-cement ratio values of lightweight aggregate concrete. The higher water-cement ratios, the lower expansion values of lightweight aggregate concrete when the relative dynamic modulus of elasticity decreased to the same degree under freezing and thawing action.

Sign in / Sign up

Export Citation Format

Share Document