scholarly journals Influence of a Retarding Admixture on the Behavior of Mortars Made from Different Types of Cement

2018 ◽  
Vol 7 (4.20) ◽  
pp. 334
Author(s):  
Tumadhir Merawi Borhan ◽  
Munaf A. Al-Ramahee ◽  
Noor Al-Hassnawi ◽  
Zaid Ali AlZaidi
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Setting Time ◽  
Length Change ◽  
Setting Times ◽  
White Cement ◽  
Cement Mortars ◽  
Different Types ◽  
Positive Effect

The effect of retarding admixture on the fresh and hardened behaviour of different types of cement mortars and pastes when using a retarding admixture was investigated in this study. The types of cement used are; White cement (WhC), Ordinary Portland cement (OPC) and Sulphate Resistant Portland cement (SRC). Different cement mortar and paste mixes were cast, for this purpose, with and without the admixture. Initial and final setting times, compressive strength, length change, absorption and density for these mixes were examined at the curing ages of 3,7,28,45 days. The results showed that the addition of retarding admixture delayed the setting time significantly of WhC paste. The retarding admixture has a positive effect on the compressive strength of the mortar specimens for all types of cement used. regarding the length change test, the admixture was found to reduce the initial expansion for all types of cement at all ages. The results also showed an increase in the density and decrease in water absorption, especially at the later ages for all types of cement.  Among all cement types used, WhC was noticeably the most affected type by using the retarding admixture compared to other types of cement used.  

Properties of Cement Mortars Mixed with SiO2 and CaCO3 Nanoparticles

2013 ◽  
Vol 539 ◽  
pp. 244-248
Author(s):  
De Zhi Wang ◽  
Yin Yan Zhang ◽  
Yun Fang Meng
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Negative Impact ◽  
Setting Time ◽  
Water Requirement ◽  
Mineral Admixtures ◽  
Cement Pastes ◽  
Optimal Replacement ◽  
Cement Mortars

Water requirement of normal consistency, setting time and soundness of cement pastes mixed with SiO2 and CaCO3 nanoparticle and the flexural strength and compressive strength of cement mortars mixed with SiO2 and CaCO3 nanoparticles were experimentally studied. Results indicated that the added nano-SiO2 and nano-CaCO3 with a mass account of 4.0 wt. % decreased the setting time and increased the water requirement of normal consistency, flexural strength and compressive strength. And these nanoscaled mineral admixtures did not have a negative impact on cement soundness. The optimal replacement levels of cement by SiO2 and CaCO3 nanoparticles for producing cement mortar with improved strength were 2.0 and 4.0 wt.% respectively.

Effect of Zeolite on Early Strength of Portland Cement Mortars

2019 ◽  
Vol 798 ◽  
pp. 358-363
Author(s):  
Raphat Tanasalagul ◽  
Thammaros Pantongsuk ◽  
Thapanee Srichumpong ◽  
Jaroon Junsomboon ◽  
Wichit Prakaypan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Testing Machine ◽  
Type I ◽  
X Ray Diffraction ◽  
Cement Mortars ◽  
Binder Ratio ◽  
Early Strength ◽  
Water To Binder Ratio

Portland cement consists essentially of compounds of lime mixed with silica and alumina whereas zeolite is a kind of minerals containing high content of reactive silica and alumina. Therefore, there is a probability to apply zeolite in cement mortar in order to develop mortar properties. The purpose of this research was to study and analyze the efficiency of zeolite addition on properties of cement mortar. X-ray diffraction (XRD), universal testing machine (UTM) and scanning electron microscope (SEM) were used to characterize for mortar specimens. Mechanical property test was compressive strength according to ASTM C109 and carried out on 5 x 5 x 5 cm3 cube specimens at 1, 7 and 28 curing days. In this research, cement mortars were prepared by mixing type I Portland cement, fly ash, sand and zeolite. Zeolite was varied as 0, 0.25, 0.50 and 0.75 wt.% to cement and w/b (water to binder ratio) was 0.48. The results presented that the compressive strength of mortar with small amount of zeolite was improved since 1day age obviously comparing to that of mortar without zeolite. It was confirmed that zeolite would help strengthening the cement mortars at early strength.

scholarly journals Effect of Polymer Addition on Performance of Portland Cement Mortar Exposed to Sulphate Attack

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 71 ◽  
Author(s):  
Paweł Łukowski ◽  
Dominika Dębska
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Chemical Resistance ◽  
Cement Mortar ◽  
Cement Composites ◽  
Distilled Water ◽  
Sulphate Attack ◽  
Polymer Addition ◽  
Cement Mortars ◽  
Time Changes

Resistance to degradation contributes greatly to the durability of materials. The chemical resistance of polymer-cement composites is not yet fully recognized. The goal of the research presented in this paper was to assess the performance of polymer-cement mortars under sulphate aggression, as compared to unmodified cement mortar. Mortars with polymer-to-cement ratios from 0 to 0.20 were stored in either a 5% MgSO4 solution or distilled water for 42 months. During this time, changes in elongation, mass, and compressive strength were determined. The results of these investigations, together with the visual and microscopic observations, allowed us to conclude that polymer–cement composites demonstrated better resistance to the attack of sulphate ions than unmodified cement mortar, even when using Portland cement with enhanced sulphate resistance.

The Influence of Alcohol Amine Admixtures on the Macroscopic Properties of Portland Cement Paste

2014 ◽  
Vol 525 ◽  
pp. 573-579
Author(s):  
Tian Yong Huang ◽  
Dong Min Wang ◽  
Ze Liu
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Cement Paste ◽  
Setting Time ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Cement Mortars ◽  
Macroscopic Properties ◽  
Initial Setting

It is studied the influence of triethanolamine (TEA), diethylenetriamine (DEA), Triisopropanolamine (TIPA), aminoethyl ethanolamine (AE), and polyvinyl alcohol ammonium phosphate (PAAP) at different dosages on the properties of fresh and hardened cement pastes and mortars prepared by Portland cement, including standard consistency water, setting time, the cement paste fluidity, and compressive and flexural strength. It is showed that the high polarity alcohol amine molecules exhibit strong chemical interactions with cement matrix, which are reflected in modified macroscopic properties of the cement system. All alcohol amine admixtures increased the standard consistency water and decreased cement paste fluidity of Portland cement. TEA significantly shortened the initial setting time and final setting time of Portland cement. On the other hand, TIPA, DEA, AE and PAAP extended the initial setting time of cement but shortened the cement final setting time. All alcohol amine admixtures except TIPA at 0.2 and 0.5 dosage increased the compressive and flexural strength of the Portland cement mortars at 3 days. Especially when the dosage of PAAP is 1, the compressive strength of the Portland cement mortars at 3 days is increased 10.5MPa. All alcohol amine admixtures except AE at 0.2 and 0.5 dosage increase the compressive and flexural strength of the Portland cement mortars at 28 days, Especially when the dosage of TIPA is 1, the compressive strength of the Portland cement mortars at 28 days is increased 8.8MPa.

scholarly journals Characteristics of Wood Ash Cement Mortar Incorporating Green-Synthesized Nano-TiO2

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Bolanle Deborah Ikotun ◽  
Akeem Ayinde Raheem
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Cement Mortar ◽  
Setting Time ◽  
Wood Ash ◽  
Partial Replacement ◽  
Nano Tio2 ◽  
Setting Times ◽  
Binder Ratio ◽  
Water To Binder Ratio

AbstractThis paper presents the findings of an investigation into the influence of green-synthesized nano-TiO2 on the characteristics of wood ash (WA) cement mortar. Mortar specimens were prepared by partial replacement of cement with WA (10% by weight) and addition of 1, 2 and 3% nano-TiO2 by weight of binder; using constant water-to-binder ratio (w/b) for all mixtures. The properties evaluated are setting time of the binder and flexural and compressive strength with water absorption of the mortar. The results indicated that addition of 1 and 2% nano-TiO2 reduced setting times of WA cement paste. Also, the flexural and compressive strength of WA cement mortar were higher with the incorporation of up to 2% nano-TiO2. The water absorption of WA cement mortar was reduced when nano-TiO2 was added with 2% incorporation having the best result. The incorporation of NT in WA cement mortar improved its workability and strength characteristics.

scholarly journals IMPLEMENTATION OF FELDSPAR AS PARTIALLY REPLACEMENT MATERIAL IN CEMENT MORTAR (EXPLORATION AND APPLICATION)

2021 ◽  
pp. 1-9
Author(s):  
Walid Edris ◽  
Mahmoud Al-Tamimi ◽  
Mohammed Aldelgawy
Keyword(s):  
Compressive Strength ◽  
Elevated Temperatures ◽  
Cement Mortar ◽  
Setting Time ◽  
Raw Material ◽  
Replacement Ratio ◽  
Cement Replacement ◽  
Residual Compressive Strength ◽  
Setting Times ◽  
Compressive And Flexural Strengths

This paper aims to explore and evaluate the use of Jordanian Feldspar as a natural resource partially replacement material for each of cement and sand in cement mortar. First, Al-Jaishia area was explored through a global positioning system (GPS) navigation to gather site samples of Feldspar raw material. Afterward, cement and sand were partially replaced by Feldspar with substitution ratios of 5%, 10%, 15%, 20%, and 25% for each. The study included the effect of cement replacement on normal consistency and setting time for cement paste. The water content along with initial and final setting times increased via the increment of cement replacement ratio. Moreover, mechanical properties (compressive, flexural, and residual compressive strengths) of cement mortar due to both cement and sand replacement were evaluated. The compressive and flexural strengths after 3, 7, and 28 days of curing were examined for both cement and sand replacement. While, residual compressive strength for cement replacement after 28 days was measured at elevated temperatures of 400°C, 600°C, and 800°C. The compressive and flexural strengths decreased by increasing the Feldspar replacement ratio for both cement and sand at all specimen ages. Whereas, heat resistance properties were improved by cement/Feldspar replacement. The best result for residual compressive strength was obtained at 15% replacement ratio and 400°C temperature.

Effect of ZnO Nanoparticles on Cement Mortar for Enhancing the Physico-Chemical, Mechanical and Related Properties

2020 ◽  
Vol 12 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Ramasamy Gopalakrishnan ◽  
Subramanian Nithiyanantham
Keyword(s):  
Mechanical Properties ◽  
Zinc Oxide ◽  
Portland Cement ◽  
Zinc Oxide Nanoparticles ◽  
Ordinary Portland Cement ◽  
Cement Mortar ◽  
Setting Time ◽  
Oxide Nanoparticles ◽  
Physico Chemical ◽  
Cement Mortars

Zincoxide nanoparticles have been incorporated into the cementitious materials for enhancing their physico-chemical and mechanical properties. The decrease in particle size will leads the increase in surface to volume ratio as compared to conventional micro-particles. In this investigation to evaluate physical, chemical and mechanical properties of Ordinary Portland Cement (OPC) containing zinc oxide nanoparticles. Zinc oxide nanoparticles used with replacement of various properties such as 0%, 1%, 2%, 3%, 4% and 5% by weight with ordinary Portland cement. The ordinary Portland cement mortar, nano zincoxide cement mortars prepared with the water-binder ratio (w/b ratio) as 0.4 and cement-sand ratio as 1:3 by weight. The prepared mortars are analyzed through compressive strength, setting time, flexural strength, porosity, water absorption, sulphate attack, electrical resistivity and with SEM analysis. The setting time of zinc oxide nano particle significantly decreased and enhanced the compressive strength of Portland cement mortar. The flexural strength outcomes showed that the cement mortars with zinc oxide nanoparticle were higher rather than Portland cement mortar. Microstructure of mortar contained zinc oxide nano particles illustrate that the nano zinc oxide particles filled the pores significantly and so large size of calcium hydroxide crystals reduced afterwards more hydration products formed.

STUDIES ON THE ACTION OF SULPHATES ON PORTLAND CEMENT: II. STEAM-CURING OF PORTLAND CEMENT MORTAR AND CONCRETE AS A REMEDY FOR SULPHATE (ALKALI) ACTION

1929 ◽  
Vol 1 (4) ◽  
pp. 359-384 ◽  
Author(s):  
T. Thorvaldson ◽  
V. A. Vigfusson ◽  
D. Wolochow
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Laboratory Study ◽  
Cement Mortar ◽  
Steam Curing ◽  
Cement Mortars ◽  
Sodium Magnesium ◽  
The Stability

A study was made of the effect of steam-curing at various temperatures between 50° and 200 °C. on the resistance of Portland cement mortars to the action of solutions of the sulphates of sodium, magnesium and calcium. The methods used consisted in comparing the expansion of steam-cured and untreated mortar specimens during exposure to the solutions, and in determining the changes in the tensile strength of the more resistant mortars after long periods of exposure.A laboratory study of steam-curing as a remedy for the action of sulphates ("alkali") on Portland cement mortars, was made by determining the effect on the stability of the mortar as indicated by changes in volume and in tensile strength on exposure to sulphate solutions at 21 °C. The effect of steam-curing on the tensile and compressive strength of mortars and concrete was also studied.

Excellent durability of epoxy modified mortars in corrosive environments

2016 ◽  
Vol 36 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Md. Mostafizur Rahman ◽  
Md. Akhtarul Islam ◽  
Md. Tamez Uddin
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Epoxy Resin ◽  
Sodium Hydroxide ◽  
Cement Mortar ◽  
Aqueous Media ◽  
Different Types ◽  
Polymer Mortar ◽  
Corrosive Environments ◽  
Masonry Mortar

Abstract The resistance of three different types of masonry mortar, namely Portland cement mortar (CM), epoxy resin-based polymer CM (PCM) and polymer mortar (PM) to corrosive aqueous media have been presented in this study. Assessment was carried out on the basis of relative loss in mass and compressive strength of the mortar specimens after immersion in different corrosive solutions such as 10 vol% sulphuric acid, 10 vol% sodium hydroxide solutions and 10 wt% brine for various periods. CM specimens were found to be vulnerable in brine, acidic and alkaline mediums, while the mortar modified with epoxy resin showed excellent resistance to the above mentioned mediums. By contrast, PM evidenced appreciable stability even after immersion for a longer period in the same environment. Experimental results suggest that the epoxy-based masonry mortars can be used as a promising external rendering material to build infrastructures.

Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Structural Properties ◽  
Mechanical Milling ◽  
Cement Mortar ◽  
Cement Mortars

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

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