scholarly journals Resistance of Recycled Aggregate Concrete to Freeze-thaw and Deicing Salts

2016 ◽  
Vol 151 ◽  
pp. 329-336 ◽  
Author(s):  
Karel Šeps ◽  
Josef Fládr ◽  
Iva Broukalová
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Deicing Salts

scholarly journals Effects of Imposed Damage on the Capillary Water Absorption of Recycled Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Gao ◽  
Zhiming Ma ◽  
Jianzhuang Xiao ◽  
Fuan Li
Keyword(s):  
Absorption Coefficient ◽  
Water Absorption ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Aggregate Concrete ◽  
Capillary Water Absorption ◽  
Freeze Thaw ◽  
Loading Level

Capillary water absorption of concrete is closely related to its pore structure, permeability, and durability. This paper intensively investigates the effects of imposed damage, including freeze-thaw damage and loading damage, on the capillary water absorption of recycled aggregate concrete (RAC). Freeze-thaw cycle test, loading test, and the experiment of capillary water absorption were carried out, respectively. The results demonstrate that the addition of recycled coarse aggregate (RCA) results in the increase in the capillary absorption behavior of RAC without imposed damage, and there exists a linear correlation between the behaviors of capillary water absorption and chloride penetration of RAC. The imposed freeze-thaw damage or load damage of RAC boosts with the increase of RCA replacement percentages after suffering the same freeze-thaw cycles or loading level. The imposed freeze-thaw damage and load damage further lead to the increase in the capillary water absorption of RAC, and the capillary absorption coefficient of RAC increases linearly with the increased RCA replacement percentages, after suffering the same freeze-thaw cycles or loading level. Furthermore, capillary absorption coefficient increases linearly with the growth of imposed freeze-thaw damage or load damage degree, which can be used to estimate the capillary absorption behavior of RAC exposed to the extreme environment.

The Properties of Fine Recycled Aggregate Concrete Containing Recycled Bricks from Construction and Demolition Waste

2018 ◽  
Vol 760 ◽  
pp. 193-198 ◽  
Author(s):  
Kristina Fořtová ◽  
Tereza Pavlů
Keyword(s):  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Natural Sand ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Recycled Fine Aggregate

This paper presents research results of recycled fine aggregate concrete testing. The main aim of this contribution is verification of properties of fine aggregate concrete with partial replacement of fine natural aggregate by recycled masonry aggregate originated from construction and demolition waste. The influence of partial replacement of natural sand to mechanical properties and freeze-thaw resistance is described. The compressive strength and flexural strength were tested at the age of 28 and 60 days and after 25, 50, 75 and 100 freeze-thaw cycles. Partial replacement of natural sand was 0, 25 and 50 % for all these tests. Prismatic specimens were examined.

scholarly journals Compressive Strength Study on the Freeze-thaw Resistance of Recycled Aggregate Concrete Members

2017 ◽  
Vol 11 (1) ◽  
pp. 270-280 ◽  
Author(s):  
Haicheng Niu ◽  
Yonggui Wang ◽  
Xianggang Zhang ◽  
Xiaojing Yin
Keyword(s):  
Compressive Strength ◽  
Mass Loss ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Replacement Rate ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Surface Scaling

Introduction: Freeze-thaw resistance of recycled aggregate concrete with partial or total replacement of recycled aggregate compared with that of natural aggregate concrete was investigated in this paper. Method: Ninety specimens were fabricated to study the influence of different recycled aggregate replacement ratios on the surface scaling, mass loss, and residual compressive strength after 100 freeze-thaw cycles. Results: The experiment results indicate that the type of recycled aggregate and its replacement ratio have significant effects on the freeze-thaw performance. The cubic compressive strength of recycled aggregate concrete is overall slightly lower than that of normal concrete. After 100 freeze-thaw cycles, the compressive strength decreases and the reduction extent increases with increasing replacement rate of recycled aggregate. The surface scaling of reinforced recycled concrete prisms tends to be more severe with the increase of freeze-thaw cycles. Conclusion: Furthermore, a notable rise in mass loss and the bearing capacity loss is also found as the substitution ratio increases. Under the same replacement rate, recycled fine aggregate causes more negative effects on the freeze-thaw resistance than recycled coarse aggregate.

Compressive Behaviour of Recycle Concrete Cubes after Freeze-Thaw Cycles

2013 ◽  
Vol 671-674 ◽  
pp. 1865-1868
Author(s):  
Tao Long ◽  
Shi Hai Dong ◽  
Shi Ming Cui ◽  
Qing Yuan Wang
Keyword(s):  
Carrying Capacity ◽  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Recycle Concrete ◽  
Ultimate Carrying Capacity

It is widely considered that crushed construction aggregate waste creates a lower compressive strength kind of concrete. This paper presents experimental investigation on axial compression strength of 18 recycled aggregate concrete cubes under the freeze-thaw test. The research has focused on the effect of the freezing-thawing test on the ultimate carrying capacity of recycled concrete cubes with different coarse aggregate replacement ratio. This study confirms that freezing-thawing cycles have a greater effect on the ultimate bearing capacity of recycled concrete cubes. Some measures should be taken to prevent the recycle concrete from the freeze-thaw damage, for example add air entraining agent to concrete.

scholarly journals Effect of Freeze–Thaw Cycles on Carbonation Behavior of Three Generations of Repeatedly Recycled Aggregate Concrete

2021 ◽  
Vol 11 (6) ◽  
pp. 2643
Author(s):  
Hui Liu ◽  
Minqi Hua ◽  
Pinghua Zhu ◽  
Chunhong Chen ◽  
Xinjie Wang ◽  
...  
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Replacement Rate ◽  
Carbonation Depth ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
The Third ◽  
Three Generations ◽  
Carbonation Resistance ◽  
Multiple Recycling

Multiple recycling of waste concrete has attracted widespread attention. This study presented the carbonation behavior of repeatedly recycled aggregate concrete (RRAC) used in a micro-frozen region. The effects of freeze–thaw cycles on the carbonation depth of three generations of RRAC with 25%, 75%, and 100% of replacement rate were evaluated. All RRAC specimens after different numbers of freeze–thaw cycles were rapidly carbonated for 28 d indoors to test the carbonation resistance of concrete. The results suggested that the carbonation depth of RRAC subjected to freeze–thaw cycles is higher than that in the non-freeze–thaw condition. This is because the freeze–thaw damages cause the internal structure of RRAC to become porous and and prone to cracking, thus providing convenient channels for CO2 to react with the alkali in the cementitious materials. With the growth of replacement rate or recycling number, RRAC reveals serious freeze–thaw damage and inferior carbonation resistance, which is due to the continuous deterioration repeatedly recycled concrete aggregate (RRCA) quality. However, when the replacement rate was 25%, the carbonation depth for the third generation of RAC was comparable to the second generation of RAC at a 75% replacement rate, and even the first generation of 100% RAC. To ensure better carbonation resistance durability of multiple recycling RAC, the low replacement rate of RRCA should be considered. For the third generation of RAC with the 100% replacement rate, its highest carbonation depth after freeze–thaw cycles was 9.16 mm, which still met the design requirements for structural use in a micro-frozen region. This indicates that it is feasible for three generations of RRAC to be used in the micro-frozen environment and that RRAC has great engineering application potential and promotional value.

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