scholarly journals Effects of Shrinkage Reducing Agent and Expansive Additive on Mortar Properties

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee
Keyword(s):  
Compressive Strength ◽  
Reducing Agent ◽  
Early Age ◽  
Alkyl Ether ◽  
Test Results ◽  
Steam Curing ◽  
Plastic Shrinkage ◽  
Compressive Strength Test ◽  
Expansive Additive ◽  
Shrinkage Reducing Agent

This research is to study the effect of mortar mixed with shrinkage reducing agent (polyoxyalkylene alkyl ether type), expansive additive (CaO type), and fly ash (hereinafter “SRA,” “EX,” and “FA,” resp.). Moreover, steam curing was studied to improve the properties of mortar. The plastic shrinkage test was conducted by using the strain gauge embedded at 0.5 cm from the surface according to the ASTM C1579-06 standard within early age followed by the total shrinkage test and compressive strength test. The test results showed that mixing both the EX and SRA increases the plastic enlargement of the mortar during the early age more than using either the EX or SRA solely. The steam curing helps to reduce the plastic shrinkage when the mortar is added with the FA and SRA while adding the EX increases the enlargement compared to the normal curing. When the EX, SRA, and FA are all added to the mortar mixing, great attention should be paid due to the increase of greater enlargement. For the compressive strength view, the steam curing increases the compressive strength in all types of mixture. The steam curing significantly helps increasing the compressive strength of mortar with combination of EX, SRA, and FA. Nevertheless, the XRD and SEM tests explain such enlargement accordingly.

Effect of Expansive Additive and Shrinkage Reducing Agent on Plastic Shrinkage of Steam-Cured Mortar

2018 ◽  
Vol 936 ◽  
pp. 207-213
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee ◽  
Shigeyuki Date
Keyword(s):  
Factorial Design ◽  
Setting Time ◽  
High Volume ◽  
Reducing Agent ◽  
Steam Curing ◽  
Initial Setting Time ◽  
Plastic Shrinkage ◽  
Initial Setting ◽  
Expansive Additive ◽  
Shrinkage Reducing Agent

This research is part of the mortar’s plastic shrinkage study. Contents in this article is related to how the Expansive Additive (EX), Shrinkage Reducing Agent (SRA), and Fly Ash (FA) help to reduce and control the shrinkage and to compare the effectiveness of these substances used in the normal curing, i.e., at 30 °C and in the steam curing process by using the factorial design with 3 factors and to be divided into 2 levels. Factors to be studied are the amount of EX, SRA and FA replacement. The test of plastic shrinkage was conducted in accordance with the ASTM C1579-06 standard, placing the strain gauge 0.5 centimeters beneath the surface in the middle of the mold, recording the shrinkage rate starting from the initial setting time for 24 hours. The results showed that, in normal curing, the EX influences the expansion while, in steam curing, the EX and SRA significantly influences the expansion. To add the FA in high volume along with the EX significantly effects the expansion for both the normal and steam curing. Furthermore, the study model and equation for plastic shrinkage of mortar are presented in the form of factor proportion to be considered from the factorial design study basis.

scholarly journals Effects of Shrinkage Reducing Agent and Expansive Additive on Plastic Shrinkage of Mortar at Different Temperatures

2018 ◽  
Vol 206 ◽  
pp. 02002
Author(s):  
Sarapon Treesuwan ◽  
Komsan Maleesee ◽  
Shigeyuki Date
Keyword(s):  
High Temperature ◽  
Setting Time ◽  
Reducing Agent ◽  
Early Age ◽  
Initial Setting Time ◽  
Plastic Shrinkage ◽  
Different Temperatures ◽  
Expansive Additive ◽  
Hot Weather ◽  
Shrinkage Reducing Agent

In the construction, it is inevitable to perform plaster work in hot weather which causes the dehydration and rapid shrinkage on the paste during the early age. This research shows the studies of reducing the plastic shrinkage of mortar during the early age with such additives as the Shrinkage Reducing Agent (SRA), the Expansive Additive (EX), and the Fly Ash (FA) in controlled temperatures at 30°C and 40°C, with relative humidity between 60% and 70% according to the ASTM C1579-06 standard, with the strain gauge installed at 0.5 cm.from the surface. The shrinkage rate was measured starting from the Initial Setting Time and every 10 minutes afterwards for 24 hours. The results show that high temperature effects the cracking and how to use different formulas of additive under different circumstances is considerably important. To use only one additive is not sufficient in high temperature. To use the SRA in addition to the EX enhances better expansion than to use only the EX. Moreover, it is recommended to pay close attention in adding large amount of the FA into mortar with the EX and SRA added which extremely enhances the expansion and potential cracking.

Influence of Metakaolin on Strength and Microstructure of Steam-Cured High-Strength Concrete

2013 ◽  
Vol 838-841 ◽  
pp. 42-46 ◽  
Author(s):  
Jun Jie Zeng ◽  
Zhi Hong Fan ◽  
Long Chen
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Pozzolanic Reaction ◽  
Early Age ◽  
Test Results ◽  
Replacement Level ◽  
Strength Concrete ◽  
Pozzolanic Reactivity ◽  
Compressive Strength Test

The influence of metakaolin (MK) on strength and microstructure of steam-cured high-strength concrete has been investigated using compressive strength test, XRD, MIP and SEM. Three MK replacement levels were considered in the study: 5%, 10% and 15% by weight of cement. A mix double blended with 10% MK and 10% slag was prepared too. Test results have indicated that MK can increase the compressive strength of steam-cured concrete, especially at early age. Compressive strength up to 90MPa at 1 and 28 days is obtained with the incorporation of 10% MK and 10% slag. When the replacement level of MK is higher than 10%, the enhancement of strength becomes less significant. Content of Ca (OH)2 crystals is decreased while content of hydrates with Al is increased due to the pozzolanic reactivity of MK. Concrete pore structure is significantly refined and a denser hydrates structure is obtained due to the pozzolanic reaction and filler effect of MK. Meanwhile, combination of aggregate and paste is enhanced too. The improvements of strength and microstructure become more obvious when MK and slag are double incorporated.

The Influence of Chemical Admixtures on the Autogenous Shrinkage Ultra-High Performance Concrete

2010 ◽  
Vol 452-453 ◽  
pp. 725-728 ◽  
Author(s):  
Jung Jun Park ◽  
Sung Wook Kim ◽  
Gum Sung Ryu ◽  
Kwang Myung Lee
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Pulse Velocity ◽  
Reducing Agent ◽  
Shrinkage Stress ◽  
Early Age ◽  
Ultra High Performance Concrete ◽  
Expansive Additive ◽  
Shrinkage Reducing Agent

Ultra-high performance concrete (UHPC) is a material developing remarkable performance with compressive strength of about 200 MPa and flexural strength of approximately 30 MPa on which research is actively conducted today. However, UHPC is also characterized by a mixing composed of a high specific quantity of binder that is a W/B ratio of about 0.2, which requires to examine the effects of the autogenous shrinkage. Accordingly, this study investigates the effects of the use of expansive additive and water reducing agent on the autogenous shrinkage of UHPC at early age. To that goal, autogenous shrinkage test and ultrasonic pulse velocity (UPV) monitoring are conducted for a mixing of UHPC using expansive additive and shrinkage reducing agent. The experimental results reveal that the autogenous shrinkage of UHPC reduces by 24% for a mix of UHPC adopting both 7.5% of expansive additive and 1% of shrinkage reducing agent compared to the mix without admixture. Furthermore, this mix is seen to compensate the autogenous shrinkage occurring at early age when UHPC develops its largest stiffness in view of the UPV evolution curve. At that time, the shrinkage stress seems to be extremely softened.

scholarly journals Analysis of The Rock Fracture on Uniaxial Compressive Strength Test

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Edward Dinoy ◽  
Yohanes Gilbert Tampaty ◽  
Imelda Srilestari Mabuat ◽  
Joseph Alexon Sutiray Dwene
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Poisson Ratio ◽  
Rock Fracture ◽  
Strength Test ◽  
Maximum Pressure ◽  
Test Results ◽  
Average Value ◽  
Compressive Strength Test ◽  
Uniaxial Compressive Strength Test

The compressive strength test is one of the technical properties or compressive strength tests that are commonly used in rock mechanics to determine the collapse point or the elasticity of rock against maximum pressure. The rock collapse point is a measure of the strength of the rock itself when the rock is no longer able to maintain its elastic properties. The purpose of this test is to find out how long the rock maintains its strength or elasticity properties when pressure is applied, and to find out the difference between the strength of compact rock and rock that has fractures when pressure is applied. Rocks that have fractures will break more easily or quickly when pressure is applied compared to compact rocks. This analysis is carried out by comparing the rock strength of each sample, both those that have fractures and compact rocks. To find out these differences, laboratory testing was carried out. The test results show the value (compressive strength test 57.76 MPa), (elastic modulus 5250.000MPa), (Poisson ratio 0.05) and the average value of rock mechanical properties test (axial 0.91), (lateral-0.279), and (volumetric 0.252) . Based on the test results above, it shows that rocks that have fractures will break more easily when pressure is applied, compared to compact rocks that have a long time in the uniaxial compressive strength test.

scholarly journals Effect of fine recycled aggregates on the properties of non-cement blended materials

2020 ◽  
Vol 323 ◽  
pp. 01018
Author(s):  
Wei-Ting Lin ◽  
Lukáš Fiala ◽  
An Cheng ◽  
Michaela Petříková
Keyword(s):  
Compressive Strength ◽  
Blast Furnace Slag ◽  
Interface Structure ◽  
Strength Test ◽  
Recycled Aggregates ◽  
Test Results ◽  
Granulated Blast Furnace Slag ◽  
Fine Aggregates ◽  
Compressive Strength Test ◽  
Furnace Slag

In this study, the different proportions of co-fired fly ash and ground granulated blast-furnace slag were used to fully replace the cement as non-cement blended materials in a fixed water-cement ratio. The recycled fine aggregates were replaced with natural fine aggregates as 10%, 20%, 30%, 40% and 50%. The flowability, compressive strength, water absorption and scanning electron microscope observations were used as the engineered indices by adding different proportions of recycled fine aggregates. The test results indicated that the fluidity cannot be measured normally due to the increase in the proportion of recycled fine aggregates due to its higher absorbability. In the compressive strength test, the compressive strength decreased accordingly as the recycled fine aggregates increased due to the interface structure and the performance of recycled aggregates. The fine aggregates and other blended materials had poor cementation properties, resulting in a tendency for their compressive strength to decrease. However, the compressive strength can be controlled above 35 MPa of the green non-cement blended materials containing 20% recycled aggregates.

BEHAVIOR OF M 50 GRADE SELF-COMPACTING CONCRETE DEVELOPED USING PORTLAND SLAG CEMENT AND METAKAOLIN

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Sravya Nalla ◽  
Janardhana Maganti ◽  
Dinakar Pasla
Keyword(s):  
Compressive Strength ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Test Results ◽  
Slag Cement ◽  
Self Compacting Concrete ◽  
Destructive Testing ◽  
Compressive Strength Test ◽  
Portland Slag Cement ◽  
Strength And Durability

Self-compacting concrete (SCC) is a revolutionary development in concrete construction. The addition of mineral admixtures like metakaolin, which is a highly reactive pozzolana to the SCC mixes, gives it superior strength and durability. The present work is an effort to study the behavior of M50 grade SCC by partial replacement of Portland Slag Cement (PSC) with metakaolin. Its strength and durability aspects are comparable with a controlled concrete (without replacement of cement). In the present work, a new mix design methodology based on the efficiency of metakaolin is adopted. The optimum percentage replacement of cement with metakaolin is obtained based on compressive strength test results. The influence of metakaolin on the workability, compressive strength, splitting tensile strength and flexural strength of SCC and its behavior when subjected to elevated temperature was investigated through evaluation against controlled concrete and non-destructive testing. From the test results, it was observed that incorporation of metakaolin at an optimum dosage satisfied all the fresh properties of SCC and improved both the strength and durability performance of SCC compared to controlled concrete.

scholarly journals Multigene Genetic Programming for Estimation of Elastic Modulus of Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Alireza Mohammadi Bayazidi ◽  
Gai-Ge Wang ◽  
Hamed Bolandi ◽  
Amir H. Alavi ◽  
Amir H. Gandomi
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Genetic Programming ◽  
High Strength Concrete ◽  
Elastic Moduli ◽  
High Strength ◽  
Test Results ◽  
Strength Concrete ◽  
Multigene Genetic Programming ◽  
Compressive Strength Test

This paper presents a new multigene genetic programming (MGGP) approach for estimation of elastic modulus of concrete. The MGGP technique models the elastic modulus behavior by integrating the capabilities of standard genetic programming and classical regression. The main aim is to derive precise relationships between the tangent elastic moduli of normal and high strength concrete and the corresponding compressive strength values. Another important contribution of this study is to develop a generalized prediction model for the elastic moduli of both normal and high strength concrete. Numerous concrete compressive strength test results are obtained from the literature to develop the models. A comprehensive comparative study is conducted to verify the performance of the models. The proposed models perform superior to the existing traditional models, as well as those derived using other powerful soft computing tools.

scholarly journals Improvement of the Early-Age Compressive Strength, Water Permeability, and Sulfuric Acid Resistance of Scoria-Based Mortars/Concrete Using Limestone Filler

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Aref Al-Swaidani ◽  
Andraos Soud ◽  
Amina Hammami
Keyword(s):  
Compressive Strength ◽  
Acid Resistance ◽  
Early Age ◽  
Test Results ◽  
Natural Pozzolan ◽  
Water Penetration ◽  
Limestone Filler ◽  
Concrete Permeability ◽  
Strength And Durability ◽  
Penetration Depths

Natural pozzolan is being widely used as cement replacement. Despite the economic, ecological, and technical benefits of its adding, it is often associated with shortcomings such as the need of moist-curing for longer time and a lower early strength. This study is an attempt to investigate the effect of adding limestone filler on the compressive strength and durability of mortars/concrete containing scoria. Sixteen types of binders with different replacement levels of scoria (0, 10, 20, and 30%) and limestone (0, 5, 10, and 15%) were prepared. The development of the compressive strength of mortar/concrete specimens was investigated after 2, 7, 28, and 90 days’ curing. In addition, the acid resistance of the 28 days’ cured mortars was evaluated after 90 days’ exposure to 5% H2SO4. Concrete permeability was also evaluated after 2, 7, 28, and 90 days’ curing. Test results revealed that there was an increase in the early-age compressive strength and a decrease in water penetration depths with adding limestone filler. Contrary to expectation, the best acid resistance to 5% H2SO4 solution was noted in the mortars containing 15% limestone. Based on the results obtained, an empirical equation was derived to predict the compressive strength of mortars.

scholarly journals An Experiment to scrutinize the impact of Lightweight Expanded Clay Aggregates (LECA) And Metakaolin on Structural Lightweight Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 323-328
Keyword(s):  
Compressive Strength ◽  
Lightweight Concrete ◽  
Relative Increase ◽  
Partial Substitution ◽  
Early Age ◽  
Test Results ◽  
Conventional Concrete ◽  
Selective Substitution ◽  
Clay Aggregates ◽  
The Impact

Lightweight concrete is to be treated as structural concrete (using LECA as CA), it must satisfy the density in range of 1120-1920 kg/m3 and strength not less than 20 N/mm². In order to accomplish required strength, LECA with metakaolin was used at different concentrations of (20% to 26%) by weight of cement at equal increments of 2%. Test results clearly indicates that, using LECA and metakaolin as selective substitution increases the compressive strength and durable properties. The prerequisite of using additional cementious material as metakaolin was to enhance the compressive strength, durability of LWC. Metakaolin content seems to lead high early age strength with relative increase in strength of 28 days. The effective content of metakaolin was 24% along with 60% LECA as partial substitution gave very much appreciable results. The percentage reduction in density recorded was 33%. The durable aspects such as resistance offered to acidic environment was also affirming when as compared to conventional concrete.

Sign in / Sign up

Export Citation Format

Share Document