Early-age hydration and mechanical properties of high volume slag and fly ash concrete at different curing temperatures

2017 ◽  
Vol 149 ◽  
pp. 367-377 ◽  
Author(s):  
Guodong Xu ◽  
Qian Tian ◽  
Jianxiong Miao ◽  
Jiaping Liu
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
High Volume ◽  
Early Age ◽  
Fly Ash Concrete ◽  
Early Age Hydration

Fly-Ash Concretes of 50% of the Replacement Ratio to Reduce the Cracking in Concrete Structures

2013 ◽  
Vol 405-408 ◽  
pp. 2665-2670 ◽  
Author(s):  
Ming Jie Mao ◽  
Qiu Ning Yang ◽  
Wen Bo Zhang ◽  
Isamu Yoshitake
Keyword(s):  
Fly Ash ◽  
Concrete Structures ◽  
High Volume ◽  
Pozzolanic Reaction ◽  
Strength Development ◽  
Early Age ◽  
Replacement Ratio ◽  
Fly Ash Concrete ◽  
Massive Concrete ◽  
Normal Strength

Fly-ash concrete used in massive concrete structure has superior advantages to reduce hydration heat. On the other hand, the fly-ash concrete has negative property of low strength development at early age because pozzolanic reaction of fly-ash activates at mature age, such as after 28 days. To investigate these characteristics of fly-ash used in concrete, the present study discusses thermal cracking possibility of fly-ash concrete by using FE analysis software. The present study employs prediction formulae proposed by Zhang and Japanese design code in the simulations. The objects in this study are normal strength concrete mixed of fly-ash up to 50% of replacement ratio to cement. The comparative investigations show that temperature effect is more significant than strength development at early age. Based on the analytical study, high volume fly-ash concretes of 30-50% of the replacement ratio can be concluded as effective and useful materials to reduce the cracking possibility in massive concrete structures. Keywords-Fly-ash concrete; Early Age, Prediction Formulae for Strength; Thermal Stress Analysis

Mechanical Properties of Class C High Volume Fly Ash Concrete with Lime Water as Mixing Water

2014 ◽  
Vol 660 ◽  
pp. 312-316
Author(s):  
Mochamad Solikin ◽  
Budi Setiawan
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
High Volume ◽  
Fly Ash Concrete ◽  
Lime Water ◽  
High Volume Fly Ash ◽  
Mixing Water

This paper reports an investigation on mechanical properties of high volume fly ash (HVFA) concrete produced using different types of mixing water i.e. tap water and saturated lime water. The mechanical properties of ordinary Portland cement concrete are also investigated as control tests. The concrete were tested for their compressive strength, flexural strength and splitting tensile strength at the curing ages of 56 days. The results showed that strength development of high volume fly ash concrete up to 56 days is lower than ordinary portal cement. In addition, the flexural strength and splitting strength of concrete are lower than ordinary Portland cement. Moreover, the use of saturated lime water as mixing water reduces the mechanical properties of class C high volume fly ash concrete.

scholarly journals Prediction models for high-volume fly ash concrete practical application: Mechanical properties and experimental database

2021 ◽  
Vol 64 (1) ◽  
pp. 19-43
Author(s):  
Jelena Dragaš ◽  
Snežana Marinković ◽  
Vlastimir Radonjanin
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Prediction Models ◽  
High Volume ◽  
Cement Concrete ◽  
Experimental Database ◽  
Fly Ash Concrete ◽  
High Volume Fly Ash ◽  
Concrete Mechanical Properties ◽  
Similar Accuracy

The analysis of available experimental results of high-volume fly ash concrete mechanical properties showed that extensive amount of research had been done so far. However, a comprehensive analysis of basic high-volume fly ash concrete mechanical properties was not found in the literature. Having that in mind, the database of 440 high-volume fly ash concrete and 151 cement concrete mixtures collected from literature was made. The application of European Code EN 1992-1-1 prediction models for cement concrete mechanical properties, as well as existing proposals for high-volume fly ash concrete properties, were statistically evaluated on the results from the database. The analysis showed that the prediction models defined in EN 1992-1-1 for compressive strength, tensile strength and for modulus of elasticity can be used for high-volume fly ash concrete, in the given form or with modifications proposed in literature, with similar accuracy and variation of results as for cement concrete. Own model for fly ash efficiency prediction was developed.

Improvement of Early-Age Strength of High-Volume Siliceous Fly Ash Concrete with Nanosilica - A Review

2018 ◽  
Vol 7 (1) ◽  
pp. 20180065 ◽  
Author(s):  
Lincy Varghese ◽  
V. V. L. Kanta Rao ◽  
Lakshmy Parameswaran
Keyword(s):  
Fly Ash ◽  
High Volume ◽  
Early Age ◽  
Fly Ash Concrete

Very High Volume Fly Ash Cements. Early Age Hydration Study Using Na2 SO4 as an Activator

2013 ◽  
Vol 96 (3) ◽  
pp. 900-906 ◽  
Author(s):  
Shane Donatello ◽  
Ana Fernández-Jimenez ◽  
Angel Palomo
Keyword(s):  
Fly Ash ◽  
High Volume ◽  
Early Age ◽  
High Volume Fly Ash ◽  
Early Age Hydration ◽  
Very High

Nanosilica Activated High Volume Fly Ash Concrete: Effects on Selected Properties

2016 ◽  
Vol 722 ◽  
pp. 157-162 ◽  
Author(s):  
Martin Labaj ◽  
Rudolf Hela ◽  
Iveta Hájková
Keyword(s):  
Fly Ash ◽  
Raw Materials ◽  
Water Pressure ◽  
Construction Material ◽  
High Volume ◽  
Strength Development ◽  
Early Age ◽  
Fly Ash Concrete ◽  
High Volume Fly Ash ◽  
Static And Dynamic Moduli

By volume, there is no other material used as much as concrete. Its mechanical properties, durability and favorable price makes concrete the perfect construction material. In last few decades, we are seeing a growing trend of partial Portland cement’s replacement with secondary raw materials, most commonly with fly ash. So-called high volume fly ash (HVFA) concretes usually contains over 50% of it. While HVFA concrete’s long-term properties and price are improved over the classical one, its early age properties are often affected negatively. Here, a highly reactive pozzolans enters the scene. Materials like microsilica and metakaolin are known to accelerate concrete’s strength development and improve early age characteristics. In this paper, nanosilica is used for this purpose. These SiO2 nanoparticles possesses a much higher surface area and thus reactivity. Three mixtures with 0, 40 a 60% portland cement’s replacement with fly ash were prepared and tested with and without addition of small amount of nanosilica. Effects on compressive strength, static and dynamic moduli of elasticity and resistivity against water pressure were observed. Results clearly demonstrates that even with dosage in the range of tenths of percent, nanosilica can significantly improve concrete’s properties.

scholarly journals Mechanical Properties of High Volume Fly Ash Concrete Reinforced with Hybrid Fibers

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Rooban Chakravarthy ◽  
Srikanth Venkatesan ◽  
Indubhushan Patnaikuni
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Polypropylene Fiber ◽  
Basalt Fiber ◽  
High Volume ◽  
Single Type ◽  
Hybrid Fibers ◽  
Brittle Behavior ◽  
Fly Ash Concrete ◽  
High Volume Fly Ash

Fly ash substitution to cement is a well-recognized approach to reduce CO2emissions. Although fly ash concrete is prone to brittle behavior, researchers have shown that addition of fibers could reduce brittle behavior. Previous research efforts seem to have utlised a single type of fiber or two types of fibers. In this research, three types of fibers, steel, polypropylene, and basalt as 0%, 0.50%, 0.75%, and 1% by volume of concrete, were mixed in varying proportions with concrete specimens substituted with 50% fly ash (class F). All specimens were tested for compressive strength, indirect tensile strength, and flexural strength over a period of 3 to 56 days of curing. Test results showed that significant improvement in mechanical properties could be obtained by a particular hybrid fiber reinforcement combination (1% steel fiber, 0.75% polypropylene fiber, and 0.75% basalt fiber). The strength values were observed to exceed previous research results. Workability of concrete was affected when the fiber combination exceeded 3%. Thus a limiting value for adding fibers and the combination to achieve maximum strengths have been identified in this research.

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