scholarly journals Selection of the Optimum Carrier for Manufacturing Water-Repellent Concrete and Durability Evaluation of Cement Mortar Using It

2020 ◽  
Vol 10 (24) ◽  
pp. 9097
Author(s):  
Chang Bok Yoon ◽  
Han Seung Lee
Keyword(s):  
Natural Zeolite ◽  
Ordinary Portland Cement ◽  
Cement Mortar ◽  
Chloride Ion ◽  
Water Repellency ◽  
Water Repellent ◽  
Penetration Test ◽  
Water Penetration ◽  
Chloride Ion Penetration ◽  
Selection Of

The purpose of this experiment was to complement the shortcomings of existing surface treatment methods and to implement water repellency inside concrete to prevent water penetration and improve the durability of concrete. Carriers to provide water repellency were fabricated using fly ash (FA), silica fume (SF), and natural zeolite which are used as admixtures for concrete. They were mixed with cement mortar, tested, and evaluated. The compressive strength of the water-repellent impregnated natural zeolite (ZWR) specimen was 83% of that of ordinary Portland cement (OPC), and its contact angle was found to be 124°. The water penetration test and chloride ion penetration test confirmed that the water absorption and total passing charge were reduced, while the porosity and pore size were improved. For the other specimens, except ZWR, water repellency was judged to be insufficient due to the low fixing ability for the water-repellent’s active ingredient. The results of evaluating the physical performance and durability of cement mortar for the selection of the optimum carrier revealed that powders other than ZWR are not suitable as a material for providing water repellency to concrete.

scholarly journals Experimental Study on the Evaluation of Physical Performance and Durability of Cement Mortar Mixed with Water Repellent Impregnated Natural Zeolite

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3288 ◽  
Author(s):  
Chang Bok Yoon ◽  
Han Seung Lee
Keyword(s):  
Natural Zeolite ◽  
Test Specimen ◽  
Cement Mortar ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Water Repellent ◽  
Chloride Diffusion Coefficient ◽  
Accelerated Carbonation ◽  
Penetration Test ◽  
Water Penetration

To complement the shortcomings of concrete surface treatment technology and improve the durability of concrete structure, the purpose of this study was to impregnate water-repellent performance into natural zeolite, which has many pores inside, to achieve water-repellent performance inside concrete. The physical performance and durability of cement mortar mixed with water-repellent natural zeolite was evaluated. Cement mortars were prepared by mixing ZWR1%, 3%, and 5% (ZWR: Zeolite + Water Repellent impregnation) in cement powder, and compressive strength, contact angle, water penetration test, resistance chloride penetration test, chloride diffusion coefficient, and accelerated carbonation test were evaluated. When the mixing ratio of ZWR increased, the compressive strength of the test specimen was reduced compared to OPC. In contact angle measurement, water penetration test, chloride penetration resistance test, chloride diffusion coefficient, and accelerated carbonation test, the ZWR-containing samples showed superior properties compared to OPC. It was found that the durability test results improved as the amount of mixing was increased, and the durability of the test specimen containing 5% ZWR was found to be the best.

scholarly journals Effect of High-Dispersible Graphene on the Strength and Durability of Cement Mortars

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 915
Author(s):  
Xiaoqiang Qi ◽  
Sulei Zhang ◽  
Tengteng Wang ◽  
Siyao Guo ◽  
Rui Ren
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Cement Mortar ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ion Penetration ◽  
Cement Mortars ◽  
Strength And Durability ◽  
Durability Performance

Graphene’s outstanding properties make it a potential material for reinforced cementitious composites. However, its shortcomings, such as easy agglomeration and poor dispersion, severely restrict its application in cementitious materials. In this paper, a highly dispersible graphene (TiO2-RGO) with better dispersibility compared with graphene oxide (GO) is obtained through improvement of the graphene preparation method. In this study, both GO and TiO2-RGO can improve the pore size distribution of cement mortars. According to the results of the mercury intrusion porosity (MIP) test, the porosity of cement mortar mixed with GO and TiO2-RGO was reduced by 26% and 40%, respectively, relative to ordinary cement mortar specimens. However, the TiO2-RGO cement mortars showed better pore size distribution and porosity than GO cement mortars. Comparative tests on the strength and durability of ordinary cement mortars, GO cement mortars, and TiO2-RGO cement mortars were conducted, and it was found that with the same amount of TiO2-RGO and GO, the TiO2-RGO cement mortars have nearly twice the strength of GO cement mortars. In addition, it has far higher durability, such as impermeability and chloride ion penetration resistance, than GO cement mortars. These results indicate that TiO2-RGO prepared by titanium dioxide (TiO2) intercalation can better improve the strength and durability performance of cement mortars compared to GO.

Influence of Recycled Aggregate Defects on the Durability of Recycled Aggregate Concrete

2014 ◽  
Vol 629-630 ◽  
pp. 173-182 ◽  
Author(s):  
Gai Fei Peng ◽  
Juan Yang ◽  
Jing Yan Wang
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Chloride Ion ◽  
Penetration Resistance ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Water Penetration ◽  
Aggregate Concrete ◽  
Chloride Ion Penetration

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.

Properties of VA/E/MMA Terpolymer Powder-Modified Mortars

2015 ◽  
Vol 1129 ◽  
pp. 169-176
Author(s):  
Sunhee Hong ◽  
Wan Ki Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cement Mortar ◽  
Mercury Porosimetry ◽  
Chloride Ion ◽  
Test Results ◽  
Polymer Powder ◽  
Chloride Ion Penetration ◽  
Redispersible Polymer Powder

This study is to examine and clarify the quality of polymer-modified mortars using a VA/E/MMA terpolymer powder as compared with polymer-modified mortars using a VAE copolymer powder. Polymer-modified mortars using general commercial redispersible polymer powders are prepared with various polymer-cement ratios, and tested for flexural and compressive strengths, tensile strength, water absorption, chloride ion penetration, carbonation and pore size distribution by mercury porosimetry. Overall, the properties of polymer-modified mortars using a VA/E/MMA terpolymer powder were superior to those of polymer-modified mortars using a VAE copolymer powder. And VA/E/MMA terpolymer powder-modified mortars showed significantly improved mechanical properties and durability in comparison with unmodified mortar. It is concluded from the test results that the modification of cement mortar with redispersible polymer powder improves the properties of unmodified mortar, and VA/E/MMA terpolymer powder has higher quality than VAE copolymer powder.

The Research of Hydrolysis Test of Silicone Water Repellent for Protecting Reinforced Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 1725-1732
Author(s):  
Zheng Yang ◽  
Zong Yang Yuan ◽  
Hong Yao Sun ◽  
Guo Liang San ◽  
Ming Xia Shen
Keyword(s):  
Calcium Carbonate ◽  
Water Absorption ◽  
Ph Value ◽  
Chloride Ion ◽  
Concrete Surface ◽  
Water Repellent ◽  
Hydrolysis Time ◽  
Base Materials ◽  
Chloride Ion Penetration ◽  
Water Repellents

It is one of the measures of improving durability of concrete structure that apply silicone water repellent on concrete surface. The characteristic of silicone water repellent is to keep the respiratory function of concrete, not to change the original appearance of the concrete, have good hydrophobic performance and can resist to chloride ion penetration. This paper studies the hydrolysis of silicone water repellents solutions with different pH by measuring the electrical conductivity, pH value, and surface tension of the solution. The results show that silicone water repellent is hydrolyzing quickly very much. The hydrolysis time will extend with the increase of the concentration of silicone water repellent. By means of impregnating sand, rubble, cement pieces and calcium carbonate (CaCO3) powder with silicone water repellents, the water absorption at different temperature and humidity are studied and compared with the same material but not impregnated. The results indicate that the water absorption of impregnated material decreases and the silicone water repellent has hydrophobicity. The higher humidity can help hydrolysis and adhesion of silicone water repellent. The higher temperature may increase water absorption of base materials impregnated with low molecule weight silicone water repellent. Low molecule weight silicone water repellent liquid is residue on the calcium carbonate powder surface.

scholarly journals Sulfate and Chloride Resistance Properties of Portland Cement Blends

2021 ◽  
Vol 12 (1) ◽  
pp. 69-75
Author(s):  
Abu Zakir Morshed ◽  
Suraiya Hashi ◽  
Nitai Biswas ◽  
Miftaul Sadik
Keyword(s):  
Linear Expansion ◽  
Chloride Ion ◽  
Sulfate Solution ◽  
Engineering Science ◽  
Penetration Test ◽  
Cylinder Test ◽  
Chloride Ion Penetration ◽  
Chloride Resistance ◽  
Mortar Bar ◽  
Permeability Of Chloride Ion

About 53% area of Bangladesh is alluvial deposited and affected by sulfate, salinity and chloride in water and soil. Existing sulfate and chloride can severely damage the building in coastal regions. In this paper durability of cement is evaluated on the basis of strength of mortar cube, concrete cylinder test. Besides the sulfate resistance is measured by change of length of the mortar bar specimens during exposure to sulfate solution and the attacking chloride properties by Rapid chloride ion penetration test using OPC, PCC, 20% FA, 30% FA and 40% FA. The strength was observed in cube sample about 40.65, 37.2MPa after 13 weeks in sulfate solution and linear expansion was obtained about 0.28% and 0.133% for OPC and PCC cement with reference to the water. The compressive strength of the cylindrical specimens was about 16.96, 18.34 MPa for OPC and PCC, respectively at the age of 28 days. The permeability of chloride ion of OPC sample was 22.8% higher than the PCC at this age. Journal of Engineering Science 12(1), 2021, 69-75

Imparting Water Repellency to Leather through an Organo Metallic Chromium Complex

2020 ◽  
pp. 52-56
Author(s):  
Muhammad Zia Ul Haq ◽  
Zaid Yahya ◽  
H. M. Masood ◽  
N. Ali ◽  
M. Ashraf ◽  
...  
Keyword(s):  
Organometallic Compounds ◽  
Water Repellency ◽  
Water Repellent ◽  
Economical Method ◽  
Chromium Complex ◽  
Metallic Chromium ◽  
Novel Applications ◽  
Selection Of

Organometallic compounds are finding novel applications and benefitting mankind in many ways. The present work relates to the development of such compounds that shall be locally available, cheap, durable and compatible water repellent for leather. The work methodology is so that first there is selection of method of preparation in which the easiest and most economical method is selected. Suitable methods of applications are then elucidated. Finally, some necessary tests of performance are conducted. There are certain weak areas, which are highlighted.

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