Microstructural properties and water penetration resistance of cementitious binder combined with water-dispersible polyurethane

Author(s):  
Keisuke Takahashi ◽  
Shingo Asamoto ◽  
Makoto Babazono ◽  
Yoshinori Matsuda
2014 ◽  
Vol 629-630 ◽  
pp. 173-182 ◽  
Author(s):  
Gai Fei Peng ◽  
Juan Yang ◽  
Jing Yan Wang

An experimental investigation was conducted on the durability of recycled aggregate concretes with the water to binder ratios of 0.26 and 0.60, including chloride ion penetration resistance test, freezing-thawing resistance test and water penetration resistance. Natural aggregate, recycled aggregate untreated and recycled aggregate treated by sulfuric acid solution, were employed. Results indicated that, 3 mol/L acid concentration and the 7 days soaking duration was the optimum to remove the attached mortars in recycled aggregate, and its removal rate could reach to 90.8%. Water penetration resistance, chloride ion penetration resistance and freezing-thawing resistance of concrete with 0.26 W/B was superior to that of concrete with 0.60 W/B. The more pores in the internal of concrete with 0.60 W/B could be attributed to that. Durability of recycled aggregate concrete, incorporating recycled aggregate treated by sulfuric acid solution, was improved. In particular, the improvement in recycled high strength concrete was significant.


1995 ◽  
Vol 32 (5) ◽  
pp. 767-782 ◽  
Author(s):  
R.C. Joshi ◽  
Gopal Achari ◽  
Shenbaga R. Kaniraj ◽  
H. Wijeweera

The main objective of this study was to understand the effect of aging on the penetration resistance of freshly deposited sands. Two types of sand, locally available river sand used as masonry sand and Beaufort Sea sand, were selected for the study. The sands were allowed to age under a constant stress of 100 kPa in a specially designed apparatus in a dry state, as well as submerged in distilled water and in simulated sea water. Penetration resistance of the sand beds was measured periodically by pushing 4 probes into the sand bed. Mineralogical and fabric studies on freshly deposited and aged sand samples were conducted to detect the effect of aging, if any, on sand grains. The results indicate that aging significantly increases the penetration resistance of sands. The rate of increase in penetration resistance was higher for the submerged sand as compared with the dry sand. The increase in penetration resistance of the sand in a dry state was attributed to rearrangement of sand grains. In the submerged state, besides the rearrangement of sand particles, partial cementation caused by precipitation of salts and probably also silica on the sand grains and in the pores resulted in the larger increase in the penetration resistance. Key words : sand, aging, penetration resistance, freezing and thawing, sea water, distilled water.


2014 ◽  
Vol 875-877 ◽  
pp. 619-623 ◽  
Author(s):  
Suppachai Sinthaworn ◽  
Wasan Teerajetgul ◽  
Attasit Sirivachiraporn

In this study, the workability, the compressive strength and the water penetration depth under pressure for concrete incorporate with quarry waste as fine aggregate were investigated. The mix proportions of concrete were set into two classes of water to cement ratio (w/c = 0.4, 0.6). The first class (C1), the mix proportion is 1.0:0.6:2.0:4.0 (Cement: Water: Fine: Coarse). And the second class (C2), the mix proportion is 1.0:0.4:1.5:3.0 and adding the superplasticizer 1% of cement weight. The natural river sand, which use in concrete, was partially replaced by quarry dust at the rates of 0% (no quarry dust), 50% and 100 % by weight of fine aggregate. The results show that concrete containing quarry wastes as fine aggregate decreased the workability and do not significantly affect the 28-day compressive strength whereas concrete incorporating with quarry dusts reduces the water penetration depth.


2019 ◽  
Vol 815 ◽  
pp. 235-240
Author(s):  
Jin Ting Bai ◽  
Zhong Quan Xue ◽  
Mei Zhou ◽  
Bin Wu

In this paper, the water penetration resistance of rubber aggregate concrete is studied by using the water penetration height method. The experiment results show that: Under the condition of the same dosage, the greater the fineness module, the better the impermeability. Under the condition of the same particle size, the higher the dosage, the better the impermeability. Moreover, the strength of rubber aggregate concrete cannot determine its impermeability. The impermeability of rubber aggregate concrete is analyzed by binary regression analysis. The results show that: Rubber aggregate content and fineness module have obvious influence on the water permeability of concrete. The established permeability regression equation can estimate the permeability height of rubber aggregate concrete, which has certain guiding significance for practical engineering.


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