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.

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.

Performance Deterioration of High Strength Concrete under Mixed Erosion and Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 1655-1660
Author(s):  
Jian Zhang ◽  
Bo Diao ◽  
Xiao Ning Zheng ◽  
Yan Dong Li
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Mass Loss ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
High Strength Concrete ◽  
High Strength ◽  
Freeze Thaw ◽  
Strength Concrete ◽  
Dynamic Modulus Of Elasticity

The mechanical properties of high strength concrete(HSC) were experimentally investigated under mixed erosion and freeze-thaw cycling according to ASTM C666(Procedure B), the erosion solution was mixed by weight of 3% sodium chloride and 5% sodium sulfate. The mass loss, relative dynamic modulus of elasticity, compressive strength, elastic modulus and other relative data were measured. The results showed that with the increasing number of freeze-thaw cycles, the surface scaled more seriously; the mass loss, compressive strength and elastic modulus continued to decrease; the relative dynamic modulus of elasticity increased slightly in the first 225 freeze-thaw cycles, then decreased in the following 75 cycles; the corresponding strain to peak stress decreased with the increase of freeze-thaw cycles. After 200 cycles, the rate of deterioration of concrete accelerated obviously.

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 the Performance of the Basalt Fiber Concrete Resistance to Freezing and Thawing

2014 ◽  
Vol 584-586 ◽  
pp. 1304-1308 ◽  
Author(s):  
Sheng Ji Jin ◽  
Zhong Liang Li ◽  
Jian Zhang ◽  
Yan Ling Wang
Keyword(s):  
Composite Material ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Performance Test ◽  
Basalt Fiber ◽  
Fiber Reinforced Concrete ◽  
Quality Loss ◽  
Freezing And Thawing ◽  
Dynamic Modulus Of Elasticity ◽  
Fiber Concrete

The concrete composite material with basalt fiber as enhancing system in it has a lot of advantages ,including excellent mechanical properties , high temperature resistant, resistant to acid and alkali, low cost, environmental protection materials and resistance production process. It has been applied to the field of construction project. Damage of northern environment of freezing and thawing on the properties of the composite material has become a new hot issue. In order to study the characteristics of basalt fiber reinforced concrete as building composite materials in the process of freezing and thawing, this research uses the freeze-thaw cycle test to carry out the performance study on change of dynamic modulus of elasticity and quality loss of basalt fiber concrete. We use basalt fiber volume content of 0, 0.1%, 0.2% and 0.3% respectively of four groups of concrete specimens as the research object, to carry them on the freezing-thawing resisting performance test research. Research results show that the performance of dynamic modulus of elasticity and quality loss of basalt fiber concrete in freezing and thawing process is obviously better than the plain concrete. The dosage of 0.3% basalt fiber concrete freezing-thawing resisting performance is the best in the four groups of concrete samples.

Durability of concrete containing chloride-based accelerating admixtures

1990 ◽  
Vol 17 (1) ◽  
pp. 102-112
Author(s):  
T. Rezansoff ◽  
D. Stott
Keyword(s):  
Calcium Chloride ◽  
Dynamic Modulus ◽  
Linseed Oil ◽  
Standard Test ◽  
Test Method ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Cement Ratio ◽  
Freeze Thaw ◽  
Water To Cement Ratio

The influence of CaCl2 or a chloride-based accelerating admixture on the freeze–thaw resistance of concrete was evaluated. Three air entrained mix designs were investigated using ASTM C666-84, Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing. All mix designs were similar, using cement contents of 340–357 kg/m3 of concrete, except for the addition of either 2% calcium chloride or 2% High Early Pozzolith, while no accelerating admixture was added to the control mix. The entire test program was repeated four times with water-to-cement ratio of 0.46 and three times with the ratio of 0.43. For the Pozzolith-accelerated concrete, half the samples were coated with boiled linseed oil in all seven series. For the control (unaccelerated) concrete, half the samples were coated with boiled linseed oil in one series for each water-to-cement ratio. Performance was monitored using the dynamic modulus of elasticity as obtained from transverse resonant frequency measurements. Weight loss of the specimens was also measured. Only the control samples (no accelerators) showed sufficient durability to satisfy the standard of maintaining at least 60% of the original dynamic modulus after 300 cycles of alternate freezing and thawing. Sealing with linseed oil showed inconsistent improvement in the durability in the various test series when defined in terms of the dynamic modulus; however, weight losses were the lowest of all categories and surface scaling was minimal. Key words: concrete, durability, freeze–thaw testing, calcium chloride, admixtures, sealants, air void system.

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