scholarly journals High-Performance Photocatalytic Cementitious Materials Containing Synthetic Fibers and Shrinkage-Reducing Admixture

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1828 ◽  
Author(s):  
Jung-Jun Park ◽  
Soonho Kim ◽  
Wonsik Shin ◽  
Hong-Joon Choi ◽  
Gi-Joon Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Cement Mortar ◽  
Glass Fibers ◽  
Cementitious Materials ◽  
Synthetic Fibers ◽  
Total Shrinkage ◽  
White Cement ◽  
Shrinkage Reducing Admixture ◽  
White Portland Cement

This study aims to examine the mechanical, shrinkage and chemical properties of photocatalytic cementitious materials containing synthetic fibers and a shrinkage-reducing admixture (SRA). Two types of titanium dioxide (TiO2) powders and white Portland cement were considered along with ordinary Portland cement (OPC) as a control. Two types of synthetic fibers, i.e., glass and polyethylene (PE), and an SRA with contents varying from 0% to 3% were also considered. Using the TiO2 powders and the white Portland cement was effective in reducing the nitrogen oxides (NOx) concentration in cement composites. The use of PE fibers was more effective than glass fibers in terms of the mechanical properties, i.e., the compressive strength and tensile performance. With the addition of TiO2 powders and SRA or the replacement of OPC with white cement, the mechanical properties of the cement mortar generally deteriorated. The total shrinkage of the mortar could be reduced by incorporating the fibers at volume fractions greater than 1%, and the glass fiber was more effective than the PE fiber in this regard. The TiO2 powders had no significant impact on the shrinkage reduction of the cement mortar, whereas the SRA and the white Portland cement effectively reduced shrinkage. The addition of 3% SRA decreased the total shrinkage by 43%, while the replacement of the OPC with white cement resulted in a 20% reduction in the shrinkage.

Research Progress on the Hydration of Portland Cement with Calcined Clay and Limestone

2021 ◽  
Vol 1036 ◽  
pp. 240-246
Author(s):  
Jin Tang ◽  
Su Hua Ma ◽  
Wei Feng Li ◽  
Hui Yang ◽  
Xiao Dong Shen
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Research Progress ◽  
Hydration Reaction ◽  
Hydration Products ◽  
Early Hydration ◽  
Calcined Clay ◽  
Dense Microstructure

The use of calcined clay and limestone as supplementary cementitious materials, can have a certain influence on the hydration of Portland cement. This paper reviewed the influence of limestone and calcined clay and the mixture of limestone and calcined clay on the hydration of cement. Both limestone and calcined clay accelerate the hydration reaction in the early hydration age and enhance the properties of cement. Limestone reacts with C3A to form carboaluminate, which indirectly stabilized the presence of ettringite, while calcined clay consumed portlandite to form C-(A)-S-H gel, additional hydration products promote the densification of pore structure and increase the mechanical properties. The synergistic effect of calcined clay and limestone stabilize the existence of ettringite and stimulate the further formation of carboaluminate, as well as the C-(A)-S-H gel, contributed to a dense microstructure.

EFFECT OF STYRENE-BUTADIENE COPOLYMER (SBR) LATEX ON MECHANICAL AND TRANSPORT PROPERTIES OF PORTLAND CEMENT MORTAR

2020 ◽  
Vol 15 (4) ◽  
pp. 185-197
Author(s):  
Daniel Hatungimana ◽  
Şemsi Yazici ◽  
Şevket Orhan ◽  
Ali Mardani-Aghabaglou
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Detrimental Effect ◽  
Cement Mortar ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Replacement Level ◽  
Cement Production ◽  
Cement Ratio ◽  
Styrene Butadiene

ABSTRACT Portland cement is extensively used as a binder in concrete production. However, with Portland cement production, 5% of the natural resources used in this production are consumed, constituting 5–7% of the total CO2 emission. In order to mitigate the environmental problems associated with cement production, styrene-butadiene rubber latex was used as cement replacement up to 20%. In this study, compressive strength, flexural strength, unit weight, water absorption, open porosity, water sorptivity and the chloride ion permeability of Portland cement mortar mixtures modified by styrene-butadiene rubber (SBR) polymeric latex were investigated. For this purpose, the sand/cement ratio and the water/cement ratio were kept constant as 3/1 and 0.5, respectively. In addition to the control mixture containing no polymer, 1, 2, 3, 5, 10 and 20 wt.% of cement was replaced with SBR. In this way, seven mortar mixtures were prepared. Mixed curing (wet cure and dry cure) method was applied to the mortar specimens. Results showed that up to a 5% replacement level, it is possible to improve the mechanical properties of cement mortars with SBR latex addition. However, at a 10% and 20% replacement level, SBR had a significant detrimental effect on the mechanical properties of polymer modified mortars. However, the transport properties decreased with the incorporation rate of SBR latex and the detrimental effect of SBR replacement was more pronounced in 20% SBR mortar mixtures.

Influence of Two Types of Nanosilica Hydrosols on Short-Term Properties of Sustainable White Portland Cement Mortar

2018 ◽  
Vol 30 (2) ◽  
pp. 04017289 ◽  
Author(s):  
Payam Hosseini ◽  
Masoume Abolhasani ◽  
Fatemeh Mirzaei ◽  
Mohammad Reza Kouhi Anbaran ◽  
Yousef Khaksari ◽  
...  
Keyword(s):  
Portland Cement ◽  
Cement Mortar ◽  
Short Term ◽  
White Portland Cement

Water Sorption of Vegetable Fiber Reinforced Polymer Composites

2016 ◽  
Vol 369 ◽  
pp. 17-23 ◽  
Author(s):  
L.H. de Carvalho ◽  
A.G. Barbosa de Lima ◽  
E.L. Canedo ◽  
A.F.C. Bezerra ◽  
W.S. Cavalcanti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Polymer Composites ◽  
Water Sorption ◽  
Glass Fibers ◽  
Fiber Reinforced Polymer ◽  
Synthetic Fibers ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Vegetable Fiber

Despite the ever-growing worldwide interest in the use of lignocellulosic fibers as reinforcement in either thermoset or thermoplastic matrices, the use of these fibers to replace synthetic ones, is limited. The reasons for these limitations are associated with the vegetable fiber’s heterogeneity, lower compatibility to most polymers, inferior durability, flammability, poorer mechanical properties and higher moisture absorption when compared with synthetic fibers. Nevertheless, despite these drawbacks, vegetable fiber reinforced polymer composites are lighter in weight, more sustainable and can be used for non-structural products. Strategies to minimize these drawbacks include fiber and or matrix modification, the use of compatibilizers, fiber drying and the concomitant use of vegetable and synthetic fibers, for the production of hybrid composites, the latter being an unquestionable way to increment overall mechanical and thermal properties of these hybrid systems. Here we present data on the water sorption of polymer composites having thermoset and thermoplastic matrices as a function of vegetable fiber identity, content and hybridization with glass fibers. Our data indicates that, regardless if the matrix is a thermoset of a thermoplastic, water absorption tends to be relatively independent of vegetable fiber identity and to be significantly dependent of its content. Fiber drying prior to composite manufacturing and hybridization with glass fibers leads to lower overall water absorption and higher mechanical properties.

Review on the Effect of Bottom Ash in Performance of Portland Cement Mortar

2015 ◽  
Vol 815 ◽  
pp. 164-169
Author(s):  
Ng Hooi Jun ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Husin ◽  
Soo Jin Tan ◽  
Mohd Firdaus Omar
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Bottom Ash ◽  
The Other ◽  
Other Hand

Utilization and suitability of bottom ash in Portland cement have been increasing significantly in recent year. Bottom ash has substantial effects on mechanical properties with different composition of replacement in mixture of bottom ash and Portland cement. Bottom ash was used to determine the feasibility of the substitution as recycling product from industry depending on the percentage of the bottom ash. On the other hand, bottom ash offers a better solution for maintaining materials characteristic of Portland cement mortar and also provide beneficial mechanical performance. The result of using bottom ash in Portland cement mortar showed that it could make better the mechanical properties and hence disposed bottom ash wastes safely in technical, economic and environmental methods.

Hybrid effects of carbon fibers on mechanical properties of Portland cement mortar

2015 ◽  
Vol 65 ◽  
pp. 1222-1228 ◽  
Author(s):  
Xiang Shu ◽  
Ryan K. Graham ◽  
Baoshan Huang ◽  
Edwin G. Burdette
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Carbon Fibers ◽  
Cement Mortar

scholarly journals IMPROVING THE VOLUMETRIC STABILITY OF WHITE CEMENT BY USING SOME ADDITIVES

2021 ◽  
Vol 25 (Special) ◽  
pp. 2-65-2-71
Author(s):  
Marwa A. Anber ◽  
◽  
Mohammed A. Abdulrehman ◽  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Polyvinyl Alcohol ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Drying Shrinkage ◽  
Limestone Powder ◽  
Mixing Ratio ◽  
White Cement ◽  
Dry Shrinkage

Abstract: This study looked at the effects of three types of additives: limestone powder, Arabian gum AG, and polyvinyl alcohol (PVA), on White Cement Mortar's Physical and Mechanical Properties the mixing ratio for dry shrinkage was 1:2. (Cement: sand) while for other tests, it was 1:2.75 (cement: sand). The limestone powder proportions are (5%, 10%, and 15%) by weight of white cement, while the AG ratios are (0.2, 0.5, and 0.8) % by weight of white cement, the polyvinyl alcohol ratios are (2%, 4%, and 6%). This study was focused at the compressive and flexural strength of the modified mortar, as well as water absorption and drying shrinkage. According to the findings, utilizing of limestone powder as additive in white cement mortar is not advised. Since it had the negative affect on dry shrinkage of the mortar. Furthermore, polymer additives such as AG and PVA significantly increase the reduction of ability of forming crack in white cement mortar. Furthermore, the optimal additive percentages of AG and PVA are 0.5 percent and 6%, respectively.

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