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.

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.

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: III. THE EFFECT OF THE ADDITION OF SILICA GEL TO PORTLAND CEMENT MORTARS ON THEIR RESISTANCE TO SULPHATE ACTION

1929 ◽  
Vol 1 (5) ◽  
pp. 385-399
Author(s):  
T. Thorvaldson ◽  
V. A. Vigfusson ◽  
D. Wolochow
Keyword(s):  
Tensile Strength ◽  
Portland Cement ◽  
Silica Gel ◽  
Magnesium Sulphate ◽  
Calcium Sulphate ◽  
Cement Mortars

The effect of substituting silica gel for a portion of the Portland cement in standard and graded-sand mortars on the expansion and loss in strength of the mortars in sulphate solutions was determined. Portland cement silica gel sand mortars were cured in steam at 100 °C. and the effect on their sulphate resistance measured; the behavior of lime-silica gel sand mortar in solutions of sodium and magnesium sulphate was also studied. It was found that the addition of silica gel to the mortar, very effective in preventing expansion and maintaining the tensile strength of the mortar in solutions of sodium, and calcium sulphate, was not so effective in solutions of magnesium sulphate. Steam-cured mortars containing silica gel to the extent of 20% of the cement present showed a slightly greater resistance to the action of solutions of sodium and calcium sulphates, but less resistance in solutions of magnesium sulphate, than similar steam-cured mortars containing no silica gel. Lime-silica gel sand mortars behaved very similarly in sulphate solutions as Portland cement mortars containing silica gel. The possible causes of the effects produced by the addition of silica gel to Portland cement mortars are considered, and several explanations discussed.

scholarly journals The Development of Nanoalumina-Based Cement Mortars for Overlay Applications in Concrete Floors

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3465 ◽  
Author(s):  
Szymanowski ◽  
Sadowski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Aluminum Oxide ◽  
Functional Properties ◽  
Abrasion Resistance ◽  
Cement Mortar ◽  
Cement Mortars ◽  
Positive Effect ◽  
Scanning Electron

This article focuses on the development of nanoalumina-based cement mortars for overlay applications in concrete floors. It focuses on the effect of applying aluminum oxide (Al2O3) nanopowder to the cement mortar used to make the overlay, on the adhesion of this overlay to concrete substrate and on its functional properties. It was claimed that the addition of 0.5% of Al2O3 nanopowder has a positive effect on the adhesion of the cement mortar used to make the overlay to the substrate made of concrete. The prior studies performed using scanning electron microscopy (SEM) confirmed that the reason for the improvement in adhesion is the fact that cement mortar used to make the overlay with the addition of 0.5% of Al2O3 nanopowder is less porous than the reference mortar within the interphase. The article concurs that the most favorable results, in terms of lower abrasion resistance and higher subsurface tensile strength of the cement mortar used to make the overlay, are mainly brought about by adding 0.5% of Al2O3 nanopowder.

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.

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.  

scholarly journals Effect of Paraffin and Silica Matrix Phase Change Materials on Properties of Portland Cement Mortars

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 921
Author(s):  
Vicente Zetola ◽  
Luis J. Claros-Marfil ◽  
Alfonso García Santos ◽  
Fco. Javier Neila González
Keyword(s):  
Portland Cement ◽  
Phase Change ◽  
Phase Change Materials ◽  
Cement Mortar ◽  
Silica Matrix ◽  
Mix Design ◽  
Limited Data ◽  
Air Content ◽  
Cement Mortars ◽  
Maximum Compressive Strength

In the search for methods to incorporate Phase Change Materials (PCM) into Portland cement mortar mixtures, PCM based on paraffins adhered to a silica-based matrix appear as a suitable option. However, paraffin particles have been observed to escape from the silica matrix when water is added. There are only limited data on how the use of such PCM affects the behaviour of mortars. To evaluate the effect of this PCM addition, Portland mortar mixtures were elaborated with 5%, 10% and 15% of PCM content, and using CEM 42.5 I R and CEM I 52.5 R cement types. Physical properties such as density, open porosity, air content and water absorption were analysed for fresh and dry samples. The results obtained show that the PCM-added mixtures require greater water and cement amounts than the standard mortar mixtures to achieve similar compressive strengths. Compared to non-PCM mixtures the PCM-added mortars present a density lowering of 37% for fresh mixtures and near 45% for dry state forms. A maximum compressive strength of 15.9 MPa was reached for 15% PCM mixtures, while values beyond 40 MPa were achieved for 5% PCM mixtures. Thus, the proposed study contributes to broad the available knowledge of PCM cement mortar mixtures behaviour and their mix design.

Physical Behavior of Ternary Portland Cement Mortar Mixtures Incorporating Pozzolan and Filler

2018 ◽  
Vol 789 ◽  
pp. 170-175
Author(s):  
Mauricio Arreola-Sanchez ◽  
Jorge Alberto Pacheco-Segovia ◽  
Hugo Luis Chávez García ◽  
Wilfrido Martínez-Molina ◽  
Elia Mercedes Alonso-Guzmán ◽  
...  
Keyword(s):  
Portland Cement ◽  
Cement Mortar ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Expanded Perlite ◽  
Physical Behavior ◽  
Cement Mortars ◽  
Indirect Tension ◽  
Simple Compression

This work shows the results carried out by mixtures of Portland cement mortars with twoadditions: ash brick ovens (CELU) which acting as pozzolan, and ground expanded perlite (PEM)as filler. The objective of this research is to determine whether by adding a pozzolan and fillermixtures base Portland cement is possible to increase physical and mechanical behavior. There were3 mixtures: the control and 2 more: one with substitution of 7% CELU, and other with 7% CELU+5%PEM respectively, carrying out tests of normal consistency, setting, fluency, simple compression,indirect tension, ultrasonic pulse velocity and electrical resistivity at the ages of 3, 7, 14, 28 and 120days. The results were favorable in the mixture that incorporates both materials (CELU+PEM).

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