scholarly journals Effect of Various Types of Superplasticisers on Consistency, Viscosity, Structure and Long-Term Strength of Geopolymer Products

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7614
Author(s):  
Łukasz Anaszewicz
Keyword(s):  
Fresh Concrete ◽  
Curing Temperature ◽  
Term Strength ◽  
Acrylic Polymer ◽  
Acrylic Polymers ◽  
Air Voids ◽  
Flow Table ◽  
Early Strength ◽  
Air Void

This article presents the results of research on the effect of plasticisers made based on four different compounds—melamine (M), naphthalene (NF), acrylic polymers (AP) and polycarboxylic ethers (PC)—added to the tested mixes in the amount of 2% of the fly ash (FA). The influence of superplasticisers (SPs) on the consistency of the fresh concrete was investigated using a flow table and a penetrometer, and the air voids content was determined by means of a porosimeter. Additionally, the influence of plasticisers on the viscosity of the paste was investigated using a rheometer. Hardened mortar that matured under two different conditions was also tested at elevated and room temperatures. The tested properties were 7-, 28- and 90-days compressive strength and internal microstructure viewed under a microscope. NF had the greatest viscosity-reducing effect while it increased the air void volume in the mix at the same time. The highest early and late strengths were obtained after curing in elevated temperature samples with an acrylic-polymer-based superplasticiser. However, the increased curing temperature of the samples only influenced the early strength results. Its effect was not visible after 90 days. The AP addition also had a significant impact on improving the consistency of the mixture. The addition of plasticisers did not affect the microstructure of the specimens.

Experimental Study of Influences of Initial Temperature on Cement Grout Performance

2015 ◽  
Vol 1095 ◽  
pp. 242-247 ◽  
Author(s):  
Jin Chao Yang ◽  
Wan Peng Wang ◽  
Shu Guang Wang ◽  
Jian Hua Chen ◽  
Wei Yang
Keyword(s):  
Experimental Study ◽  
Initial Temperature ◽  
Setting Time ◽  
Cement Grout ◽  
Curing Temperature ◽  
Term Strength ◽  
Bleeding Rate ◽  
Early Strength

Through the experiment, this paper studies and analyzes influence of different initial temperatures on cement grout performance. The results show initial temperature has influences on grout fluidity, bleeding rate, setting time and early strength. Under guaranteed curing temperature, initial temperature has no influence on long-term strength of grout.

Study on the Strength of Sea Sand Concrete in Ningbo

2011 ◽  
Vol 250-253 ◽  
pp. 262-265
Author(s):  
Jun Zhe Liu ◽  
Guo Liang Zhang ◽  
Jian Bin Chen ◽  
Zhi Min He
Keyword(s):  
Fly Ash ◽  
Influence Factor ◽  
Concrete Strength ◽  
Chloride Ion ◽  
Strength Development ◽  
Term Strength ◽  
Two Phase ◽  
Sea Sand ◽  
Early Strength

This paper mainly explain and expounded folding compressive strength of the different types of sea sand mortar , fly ash to the sea sand concretes mortar intensity influence as well as the chloride ion content to the sea sand concretes mortar intensity influence. The pulverized fly ash has the postponement function to the sea sand concretes early strength, the chloride ion has the promoter action to the sea sand concretes early strength. 20% pulverized fly ash be good to the sea sand concretes long-term strength development influence, can achieve the goal which enhances the sea sand concretes the long-term strength . The chloride ion is greater to the concretes early strength influence, especially in previous 3 days. Along with the time development, the chloride ion influence weakens, but the pulverized fly ash enlarges to the concretes intensity's influence factor. A two-phase arrived, the final concrete strength values close to each other.

Effect of Hydration of Unreacted Cement in Hardened Mortar with Low W/C on the Long-Term Strength

2009 ◽  
Vol 405-406 ◽  
pp. 350-355 ◽  
Author(s):  
Xiao Xin Feng ◽  
Xiao Hua Sun ◽  
Xiao Yan Wang ◽  
Qing Min Wei
Keyword(s):  
Curing Temperature ◽  
Term Strength ◽  
Hydration Degree

Through accelerating the hydration by heighening the curing temperature, the effect of the hydration of the unreacted cement in the hardened mortar with low W/C on the long-term strength was investigated. The results show that in the hardened mortar with low W/C, there exists a lot of unreacted cement at the age of 28 days, and when these cement particles hydrate again at the long age, it is disadvantageous to the long-term strength of the mortar. Moreover, the lower the W/C, the lower the hydration degree at the earlier age, and the more disadvantageous to the development of strength at the long age.

scholarly journals Effects of Mixing and Curing Temperature on the Strength Development and Pore Structure of Fly Ash Blended Mass Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ki-Bong Park ◽  
Takafumi Noguchi
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Pore Structure ◽  
Weather Conditions ◽  
Strength Loss ◽  
Curing Temperature ◽  
Strength Development ◽  
Mass Concrete ◽  
Term Strength

The aim of this work is to know clearly the effects of temperature in response to curing condition, hydration heat, and outside weather conditions on the strength development of high-performance concrete. The concrete walls were designed using three different sizes and three different types of concrete. The experiments were conducted under typical summer and winter weather conditions. Temperature histories at different locations in the walls were recorded and the strength developments of concrete at those locations were measured. The main factors investigated that influence the strength developments of the obtained samples were the bound water contents, the hydration products, and the pore structure. Testing results indicated that the elevated summer temperatures did not affect the early-age strength gain of concrete made using ordinary Portland cement. Strength development was significantly increased at early ages in concrete made using belite-rich Portland cement or with the addition of fly ash. The elevated temperatures resulted in a long-term strength loss in both belite-rich and fly ash containing concrete. The long-term strength loss was caused by a reduction in the degree of hydration and an increase in the total porosity and amount of smaller pores in the material.

scholarly journals Effect of percent air voids content on the deformation properties of the asphalt mixture

2021 ◽  
Vol 1209 (1) ◽  
pp. 012078
Author(s):  
J Bokomlasko ◽  
J Mandula
Keyword(s):  
Laboratory Tests ◽  
Asphalt Mixture ◽  
Road Construction ◽  
Air Voids ◽  
Aggregate Fraction ◽  
Deformation Properties ◽  
Load Effects ◽  
Air Void

Abstract Asphalt mixture is a building material with many advantages. Therefore, it is most used in road construction. If the asphalt mixture is laid with the prescribed technology, it can withstand load effects to long-term. It is necessary to take samples that will be subjected to laboratory measurements. There are several laboratory test, for example measurement thickness of the asphalt mixture layers, the aggregate fraction, quantity of binder in the mixture, determination of air void in asphalt mixture layers. Samples taken directly from the construction site are subjected to laboratory tests. This article focuses on one of the laboratory tests and it is determination of air void in asphalt mixture layers. The determination of air void in asphalt mixture layers is test in detail, because this effect has influence on the deformation properties of asphalt mixture layers. Therefore, it was necessary to model of air void in asphalt mixture layers with different degrees air void. On this purpose was use program Abaqus. The results were plotted. This graphs showed that increasing the air void in asphalt mixture layers has effect on the expansion of deformations. This can lead to faster pavement degradation.

Effect of micro air void system on the permeability of latex-modified concretes with ordinary Portland and very early strength cements

2007 ◽  
Vol 34 (8) ◽  
pp. 895-901 ◽  
Author(s):  
K K Yun ◽  
D H Kim ◽  
K J Kim
Keyword(s):  
Image Analysis ◽  
Specific Surface ◽  
Average Distance ◽  
Chloride Permeability ◽  
Air Voids ◽  
Spacing Factor ◽  
Void System ◽  
Early Strength ◽  
Air Void ◽  
The Impact

This study focused on the impact of the micro air void system on the chloride permeability of latex-modified concretes with ordinary Portland and very early strength cements. The micro air void system was analyzed with the image analysis method. The results of this study will help field engineers and researchers gain a better understanding of the chloride permeability characteristics of latex-modified concretes. The results show that the latex-modified concretes made with both Portland and very early strength cements have more micro air voids, ranging 50 to 500 µm, than ordinary concretes. These small air voids decrease the spacing factor, which is defined as half the average distance that unstable water must travel to reach an escape boundary. The specific surface ranges from 8 to 27 mm–1 and the spacing factor ranges from 275 to 602 µm for ordinary Portland and very early strength cement concretes without and with latex modification. The specific surface tends to decrease as the spacing factor increases. The spacing factors of concretes tend to decrease with latex modification and with very early strength cement. It seems clear that the use of polymer latex in concrete can significantly lower the value of the air void spacing factor by entraining a large number of micro air voids (below 100 µm in diameter). Key words: latex-modified concrete (LMC), micro air void system, chloride permeability, image analysis.

Influence of initial curing temperature on the long-term strength of concrete

2013 ◽  
Vol 65 (6) ◽  
pp. 358-364 ◽  
Author(s):  
Runxiao Zhang ◽  
Nannan Shi ◽  
Dahai Huang
Keyword(s):  
Curing Temperature ◽  
Term Strength

Effect of Red Mud on Mechanical Properties of Loess–Containing Aluminosilicate Based Cementitious Materials

2009 ◽  
Vol 610-613 ◽  
pp. 155-160
Author(s):  
Jian Hua Wan ◽  
Heng Hu Sun ◽  
Ying Ying Wang ◽  
Chao Li
Keyword(s):  
Mechanical Properties ◽  
Red Mud ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
The Other ◽  
Term Strength ◽  
Other Hand ◽  
Early Strength ◽  
The One

The effect of the thermal treated red mud on mechanical properties of loess –containing aluminosilicate based cementitious materials is investigated. And the characteristic of hydration production is tested using XRD, SEM and EDAX methods. The results show that the thermal treated red mud not only has excellent cementitious properties but also can improve the mechanical properties of loess –containing aluminosilicate based cementitious materials. Moreover when the content of red mud is 5%, the improved effect is optimal. On the one hand, the alkaline ingredients of red mud can promote abundant ettringites to produce at early ages. And the ettringites contribute to early strength of the cementitious material. On the other hand, the content of red mud is too high to improve the long-term strength.

Effect of Curing Method on the Strength Development and Freezing-Thawing Durability of the Concrete Incorporating High Volume Blast-Furnace Slag Subjected to Initial Frost Damage

2012 ◽  
Vol 602-604 ◽  
pp. 962-967 ◽  
Author(s):  
Kyung Taek Koh ◽  
Gum Sung Ryu ◽  
Jang Hwa Lee
Keyword(s):  
Blast Furnace Slag ◽  
High Volume ◽  
Frost Damage ◽  
Strength Development ◽  
Term Strength ◽  
Water Curing ◽  
Early Strength ◽  
Curing Method ◽  
Furnace Slag

In the case of construction with high volume blast-furnace slag(BFS) concrete during winter season, the setting and hardening are drastically delayed, so it has a high risk of initial frost. Assuming that the concrete incorporating a high volume of BFS is affected by freezing at the early age during the winter conditions, then this study is to investigate the effect of curing method on the strength development and the resistance to freezing-thawing action. As a result, the concrete performing water curing at 5°C after subjected to initial frost damage improve the long-term strength and the freezing-thawing durability. The concrete implementing water curing at 30°C enhance the long-term strength and the resistance to freezing-thawing action as well as the early strength. However, the concrete with sealed curing at 30°C exhibits the improvement in the early strength, but not in the long-term strength and the freezing-thawing durability.

Long-term strength prediction of concrete with curing temperature

2005 ◽  
Vol 35 (10) ◽  
pp. 1961-1969 ◽  
Author(s):  
Seong-Tae Yi ◽  
Young-Ho Moon ◽  
Jin-Keun Kim
Keyword(s):  
Curing Temperature ◽  
Strength Prediction ◽  
Term Strength
Sign in / Sign up

Export Citation Format

Share Document