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.

STUDIES ON THE ACTION OF SULPHATES ON PORTLAND CEMENT: I. THE USE OF THE EXPANSION METHOD IN THE STUDY OF THE ACTION OF SULPHATES ON PORTLAND CEMENT MORTAR AND CONCRETE

1929 ◽  
Vol 1 (3) ◽  
pp. 273-284
Author(s):  
T. Thorvaldson ◽  
D. Wolochow ◽  
V. A. Vigfusson
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Expansion Method ◽  
Cement Mortars

This paper describes the methods employed in the use of expansion measurements as a means of studying the action of sulphates on Portland cement, and on Portland cement mortars. Experimental data are given dealing with the reproducibility of the expansion measurements and the relation between expansion and loss of tensile strength of mortars. Results obtained with standard sand mortars and graded sand mortars of varying richness of mix prepared from cements which differ in their resistance to sulphate action are presented.

STEAM CURING OF PORTLAND CEMENT MORTARS. A NEW CRYSTALLINE SUBSTANCE.: (Preliminary Paper)

1929 ◽  
Vol 1 (2) ◽  
pp. 148-154 ◽  
Author(s):  
T. Thorvaldson ◽  
G. R. Shelton
Keyword(s):  
Portland Cement ◽  
Great Increase ◽  
Chemical Properties ◽  
Hydrated Lime ◽  
Crystalline Material ◽  
Saturated Steam ◽  
Crystalline Substance ◽  
Steam Curing ◽  
Cement Mortars ◽  
The Stability

The steam-curing of Portland Cement Mortars in saturated steam at 100°, 125°, 150°, 175° and 200 °C. was studied both as to variations in the tensile strength of 2-day and 28-day mortar briquets and as to the changes which occurred in the crystalline matter in the cement. The rate of hydration of the cement, as shown by the disappearance of the original crystalline material, increased with the temperature of the saturated steam. Crystals of calcium hydroxide appeared almost at once, but after reaching a maximum decreased again in amount. At the same time, a new crystalline product appeared and increased in quantity as the amount of hydrated lime decreased. Some of the chemical properties of the new crystals are given. The stability of the new crystals when exposed to solutions of sulphates indicates that the great increase in the resistance of Portland cement mortars to alkali action produced by steam-curing is connected with the production of this crystalline material.

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.

Fluid Transport Mechanisms in Portland Cement Mortar Modified with PVA and Nano Montmorillonite

2013 ◽  
Vol 687 ◽  
pp. 311-315 ◽  
Author(s):  
Teresa María Piqué ◽  
Luis Fernandez Luco ◽  
Analía Vázquez
Keyword(s):  
Tensile Strength ◽  
Portland Cement ◽  
Construction Industry ◽  
Fluid Transport ◽  
Cement Mortar ◽  
Drying Shrinkage ◽  
Cement Matrix ◽  
Poly Vinyl Alcohol ◽  
Cement Mortars ◽  
Compressive And Flexural Strengths

The development of new materials for specific applications is an increasing field in the construction industry, so is the employment of nanotechnology for this goal. When poly(vinyl alcohol) (PVA) is added to a Portland cement mortar, a film is formed in between the hydration products. This film has low elasticity modulus and high tensile strength and it enhances the mortar’s mechanical properties in the fresh and hardened states. The addition of nano montmorillonites (MMT) gives the polymer a better compatibility with the cement matrix. In this work, the changes in the microstructure of Portland cement mortars modified with PVA and PVA with MMT are assessed by means of transport of fluids capacity as an indicator. The reference is a standard mortar according to EN 196-1. The parameters measured are: weight loss under drying and air permeability. Complementary measures, such as compressive and flexural strengths and drying shrinkage have also been performed. From the obtained results, it can be concluded that the inclusion PVA + MMT to Portland cement mortar doesn’t affect the microstructure, when compared with Portland cement mortar with PVA, and even increase its tensile 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.

scholarly journals Strength and Drying Shrinkage of Alkali-Activated Slag Paste and Mortar

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mao-chieh Chi ◽  
Jiang-jhy Chang ◽  
Ran Huang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Liquid Slag ◽  
Drying Shrinkage ◽  
Curing Temperature ◽  
Alkali Activated Slag ◽  
Cement Mortars ◽  
Activated Slag ◽  
Alkali Activated

The aim of this study is to investigate the strengths and drying shrinkage of alkali-activated slag paste and mortar. Compressive strength, tensile strength, and drying shrinkage of alkali-activated slag paste and mortar were measured with various liquid/slag ratios, sand/slag ratios, curing ages, and curing temperatures. Experimental results show that the higher compressive strength and tensile strength have been observed in the higher curing temperature. At the age of 56 days, AAS mortars show higher compressive strength than Portland cement mortars and AAS mortars with liquid/slag ratio of 0.54 have the highest tensile strength in all AAS mortars. In addition, AAS pastes of the drying shrinkage are higher than AAS mortars. Meanwhile, higher drying shrinkage was observed in AAS mortars than that observed comparable Portland cement mortars.

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.  

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.

scholarly journals Assessment of the influence of fine aggregates on Portland cement mortar compressive strength

2021 ◽  
pp. 100182
Author(s):  
Alberto Muciño ◽  
Lauro Bucio ◽  
Eligio Orozco ◽  
Sofía Vargas ◽  
Nora A. Pérez
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Mortar ◽  
Fine Aggregates

scholarly journals Properties of Calcium Sulfoaluminate Cement Mortar Modified by Hydroxyethyl Methyl Celluloses with Different Degrees of Substitution

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2136
Author(s):  
Shaokang Zhang ◽  
Ru Wang ◽  
Linglin Xu ◽  
Andreas Hecker ◽  
Horst-Michael Ludwig ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Bond Strength ◽  
Cement Mortar ◽  
Retention Rate ◽  
Methyl Cellulose ◽  
Tensile Bond Strength ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Cement Mortars

This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye’elimite were selected. Properties of cement mortar in fresh and hardened states were investigated, including the fluidity, consistency and water-retention rate of fresh mortar and the compressive strength, flexural strength, tensile bond strength and dry shrinkage rate of hardened mortar. The porosity and pore size distribution were also analyzed by mercury intrusion porosimetry (MIP). Results show that HEMCs improve the fresh state properties and tensile bond strength of both types of CSA cement mortars. However, the compressive strength of CSA cement mortars is greatly decreased by the addition of HEMCs, and the flexural strength is decreased slightly. The MIP measurement shows that HEMCs increase the amount of micron-level pores and the porosity. The HEMCs with different MS/DS have different effects on the improvement of tensile bond strength in different CSA cement mortars. PAAm modification can improve the tensile bond strength of HEMC-modified CSA cement mortar.

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