Effects of high temperature and post-fire-curing on compressive strength and microstructure of calcium carbonate whisker-fly ash-cement system

Barite concrete with density grade of 3 and strength grade of C30 was prepared by mixing with different fineness of fly ash. The workability, mechanical properties and long-term high temperature performance of the prepared barite concrete were researched. Results show that the workability of barite concrete is improved by mixing with fly ash, and no segregation of mixture has been observed. The apparent density and 3d, 28d compressive strength of barite concrete are decreased obviously after mixing with fly ash. But with the increasing of the fineness of fly ash, the apparent density and 3d, 28d compressive strength of barite concrete have a slight increase. High temperature residual compressive strength is decreased with the increasing of temperature. The cycle times of heat treatment at 400°C only has a little effect on residual compressive strength of barite concrete.

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Investigation on Thermal Stability of Geopolymer Based Zeolite in Fire Case Study

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1009.31 ◽

2020 ◽

Vol 1009 ◽

pp. 31-36

Author(s):

Kanokwan Kanyalert ◽

Prinya Chindaprasirt ◽

Duangkanok Tanangteerapong

Keyword(s):

Weight Loss ◽

Compressive Strength ◽

High Temperature ◽

Fly Ash ◽

Alkali Activation ◽

Different Types ◽

Temperature Exposure ◽

In Fire ◽

Thermal Stability Of

This work aims to reveal the effects of zeolite on properties of fly ash based geopolymer under high temperature at 300 °C, 600 °C and 900 °C. The specimens were prepared by alkali activation of fly ash, which was partially replaced by two different types of zeolite at 10%, 20% and 30% by weight. The specimens were analyzed for the maximum compressive strength, weight loss percentage, XRD and SEM. The results highlighted that the percentage of weight loss increased with the ratio of zeolite replacement. The compressive strength of geopolymer with synthetic zeolite and natural zeolite at 7, 28, 60 days were similar. The high-temperature exposure resulted in the reduction in compressive strength in all proportions. At the same temperature, compressive strength of all specimens were not significantly different.

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Research on Mechanism of Architectural Wastes Solidified by Alkali-Activated Cement and Fly Ash

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.2708 ◽

2012 ◽

Vol 446-449 ◽

pp. 2708-2713 ◽

Cited By ~ 1

Author(s):

Qin Li ◽

Xiao Jun Zhou ◽

Zhuo Yin Jiang ◽

Ke Wei Sun

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Hydration Products ◽

Testing Methods ◽

Fly Ashes ◽

Comparison Research ◽

Cement System ◽

Cementitious System ◽

Micro Morphology ◽

Alkali Activated

An comparison research on the effect of pozzolanic reactions of fly ashes in architectural wastes recycle is described in the paper. In the experiment, NaOH and Na2SO4-Ca(OH)2 were used to activate the pozzolanic activities in the fly ashes—cement system to solidify the architectural wastes. The macro and micro testing methods were used to test the compressive strength, phase and electronic micro morphology of the hydration of alkali-activated fly ashes—cement cementitious system. The testing result shows that proper alkali-activated fly ashes—cement cementitious architectural wastes can shorten the incubation time of the pozzolanic reactions of fly ashes, whi ch make the reactions of fly ashes more sufficient. So the hydration products of fly ashes —cement cementitious system with alkali additions were more than those of without alkali add itions, and the compressive strength of the alkali-activated fly ashes—cement cementitious system is higher than that of non alkali-activated fly ashes—cement cementitious system.

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The effect of high temperature on compressive strength and splitting tensile strength of structural lightweight concrete containing fly ash

Construction and Building Materials ◽

10.1016/j.conbuildmat.2007.07.033 ◽

2008 ◽

Vol 22 (11) ◽

pp. 2269-2275 ◽

Cited By ~ 114

Author(s):

Harun Tanyildizi ◽

Ahmet Coskun

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

High Temperature ◽

Fly Ash ◽

Lightweight Concrete ◽

Splitting Tensile Strength

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Influences of Initial Curing Conditions on the Microstructure of Fly Ash Cement System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.168-170.532 ◽

2010 ◽

Vol 168-170 ◽

pp. 532-536 ◽

Cited By ~ 1

Author(s):

Guo Li ◽

En Li Lu ◽

Peng Wang ◽

Ou Geng ◽

Yong Sheng Ji

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Cement Mortar ◽

Early Age ◽

Concrete Durability ◽

Cement Concrete ◽

Hydration Degree ◽

Curing Conditions ◽

Cement System ◽

C 30

In order to study the influences of initial curing conditions on fly ash (FA) cement concrete durability, fly ash cement samples with 30% replacement ratio were fabricated and cured in water at 10°C, 20°C, 30°Cand 40°C for 3d, 7d, 14d and 28d respectively. Hydration degrees of fly ash at early age were measured using the selective dissolve method. Correspondingly the pore structure and morphology of FA-cement mortar and compared cement mortar were studied by using MIP and SEM methods. Then early age compressive strengths of FA-cement concrete and compared normal cement concrete were tested. Experimental results show that initial curing temperatures and ages are important factors to fly ash early age hydration degree, FA-cement system microstructure, morphology and early age compressive strength etc. High curing temperatures and longer curing time can lead higher fly ash hydration degree, and then higher compressive strength of FA-cement concrete, and make the micro-structures of fly ash-cement system denser.

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