scholarly journals Effect of Lightweight Foamed Concrete Confinement with Woven Fiberglass Mesh on its Drying Shrinkage

2021 ◽  
Vol 36 (1) ◽  
pp. 21-28
Author(s):  
Anisah Mat Serudin ◽  
Md Azree Mydin Othuman ◽  
Abdul Naser Abdul Ghani
Keyword(s):  
Drying Shrinkage ◽  
Concrete Confinement ◽  
Foamed Concrete

scholarly journals The performance of ultra-lightweight foamed concrete incorporating nanosilica

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Mohamed Abd Elrahman ◽  
Pawel Sikora ◽  
Sang-Yeop Chung ◽  
Dietmar Stephan
Keyword(s):  
Wall Thickness ◽  
Probabilistic Approach ◽  
Drying Shrinkage ◽  
Dry Density ◽  
Optimal Dosage ◽  
X Ray ◽  
Mechanical And Physical Properties ◽  
Fresh State ◽  
Foamed Concrete ◽  
The Stability

AbstractThis paper aims to investigate the feasibility of the incorporation of nanosilica (NS) in ultra-lightweight foamed concrete (ULFC), with an oven-dry density of 350 kg/m3, in regard to its fresh and hardened characteristics. The performance of various dosages of NS, up to 10 wt.-%, were examined. In addition, fly ash and silica fume were used as cement replacing materials, to compare their influence on the properties of foamed concrete. Mechanical and physical properties, drying shrinkage and the sorption of concrete were measured. Scanning electron microscopy (SEM) and X-ray microcomputed tomography (µ-CT) and a probabilistic approach were implemented to evaluate the microstructural changes associated with the incorporation of different additives, such as wall thickness and pore anisotropy of produced ULFCs. The experimental results confirmed that the use of NS in optimal dosage is an effective way to improve the stability of foam bubbles in the fresh state. Incorporation of NS decrease the pore anisotropy and allows to produce a foamed concrete with increased wall thickness. As a result more robust and homogenous microstructure is produced which translate to improved mechanical and transport related properties. It was found that replacement of cement with 5 wt.-% and 10 wt.-% NS increase the compressive strength of ULFC by 20% and 25%, respectively, when compared to control concrete. The drying shrinkage of the NS-incorporated mixes was higher than in the control mix at early ages, while decreasing at 28 d. In overall, it was found that NS is more effective than other conventional fine materials in improving the stability of fresh mixture as well as enhancing the strength of foamed concrete and reducing its porosity and sorption.

scholarly journals WATER ABSORPTION AND DRYING SHRINKAGE OF RECYCLED FOAMED AGGREGATE CONCRETE

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Chai Teck Jung ◽  
Tang Hing Kwong ◽  
Koh Heng Boon
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Drying Shrinkage ◽  
Casting Process ◽  
Concrete Specimen ◽  
Sieve Analysis ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Water Absorption Rate ◽  
Foamed Concrete

Abstract: This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period.

THE EFFECT OF OIL PALM ASH INCORPORATION IN FOAMED CONCRETE

2015 ◽  
Vol 75 (5) ◽  
Author(s):  
Farah A. Hadi ◽  
Hanizam Awang ◽  
Muhammed Zuhear Almulali
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Oil Palm ◽  
Drying Shrinkage ◽  
Target Density ◽  
Concrete Mix ◽  
Different Ages ◽  
Foamed Concrete ◽  
Oil Palm Ash ◽  
Enhanced Properties

This paper investigates the effect of replacing different portions of cement by fine oil palm ash (FOPA). A target density of 1000 kg/m3 was used for the foamed concrete mixes. A foamed concrete mix of 1 part binder, 2 parts filler and 0.45 part of water has been used. Cement was replaced at levels of 25, 35, 45, 55 and 65% by weight of binder. The compressive strength, density, water absorption, drying shrinkage and sorptivity were tested at different ages. The mix containing 25% of fine OPA showed enhanced properties in comparison to the control mix at the age of 90 days. The mixed showed higher compressive strength, less water absorption, increased density and lesser sorptivity. However, the same mix showed higher shrinkage readings than that of the control mix. 

scholarly journals Compressive Strength and Dimensional Stability of Palm Oil Empty Fruit Bunch Fibre Reinforced Foamed Concrete

2018 ◽  
Vol 65 ◽  
pp. 02001 ◽  
Author(s):  
Siong Kang Lim ◽  
Hock Yong Tiong ◽  
Kai Siong Woon
Keyword(s):  
Compressive Strength ◽  
Palm Oil ◽  
Dimensional Stability ◽  
Performance Index ◽  
Weather Condition ◽  
Drying Shrinkage ◽  
Cement Matrix ◽  
Strength Performance ◽  
Curing Conditions ◽  
Foamed Concrete

Rapid drying shrinkage is an important factor in causing cracks of concrete. This research was aimed at studying the effects of Palm Oil Empty Fruited Bunch (POEFB) fibre on the drying shrinkage behaviour and compressive strength of foamed concrete (FC) under two different curing conditions. The adopted curing conditions were air curing and tropical natural weather curing. Two volume fractions of POEFB fibre were used, which were 0.25% and 0.50% based on dry mix weight with 1-2 cm in length. The dimensional stability of the control specimen and POEFB fibre reinforced FCs was obtained by cumulating the measured linear shrinkage or expansion due to different curing conditions. The results from the two different specimens were compared. The results showed that specimens reinforced with POEFB fibre and cured under tropical natural weather condition attained lesser variations of dimensional stability and higher 90-day strength performance index than the reference mix without POEFB fibre. This improvement was attributed to the ability of POEFB fibre to bridge the cement matrix, and irregular wetting process under tropical natural weather curing condition had enabled more production of Calcium Silicate Hydrate gels that gradually blocked the penetration of water into the specimens and increased the compressive strength. It is observed that 11.43% and 4.46% of improvement in 90-day strength performance index were obtained in natural weather cured 0.5% of POEFB fibre reinforced specimen, with corresponded to the reference mix and 0.25% of POEFB fibre reinforced specimens, respectively.

Effect of Steel and Alkaline-Resistance Glass Fibre on Mechanical and Durability Properties of Lightweight Foamed Concrete

2012 ◽  
Vol 626 ◽  
pp. 404-410 ◽  
Author(s):  
Muhammad Hafiz Ahmad ◽  
Hanizam Awang
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Water Absorption ◽  
Glass Fibre ◽  
Steel Fibre ◽  
Drying Shrinkage ◽  
Early Age ◽  
Durability Properties ◽  
Alkaline Resistance ◽  
Foamed Concrete

This paper investigates the effect of steel fibre and alkaline-resistance glass fibre lightweight foamed concrete with fly ash inclusion towards mechanical and durability properties. The lightweight foamed concrete (LFC) with a density of 1000 kg/m3with constant water sand ratio of 1: 1:5 and water cement ratio of 0.45 was cast and tested. Steel and alkaline-resistance glass fibres were used as additives and 30% of cement was replaced by fly ash. Detail experiments were setup to study the behaviour and reaction of additives which is expected to give different results on mechanical and durability properties of LFC. Compared to AR-glass fibre, steel fibre has greater contribution in terms of mechanical properties. SFLFC resulted as the most effective approach for compressive, flexural, tensile split and water absorption with strength 6.13 N/mm2, 1.96 N/mm2, 1.52 N/mm2and lowest water absorption at 6.5% respectively. On the other hand, AR-glass fibre is better in controlling drying shrinkage which leads to controlling the cracking at early age. Fly ash does not change the mechanical properties and durability due to unprocessed stage to its finer forms.

scholarly journals Some Engineering Properties of Foamed Concrete for Sustainable Technological Development

2021 ◽  
Vol 6 (3) ◽  
pp. 53-57
Author(s):  
Felix A. Oginni ◽  
Samuel N. John
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Comparative Study ◽  
Modulus Of Elasticity ◽  
Technological Development ◽  
Drying Shrinkage ◽  
Engineering Properties ◽  
Dry Density ◽  
Concrete Production ◽  
Foamed Concrete

A study of the technology of foamed concrete production is carried out. The engineering properties and applications of this type of concrete are presented for varying densities so as to effectively tap the advantages of its use for specific purposes. The properties considered are the 7-day compressive strength, thermal conductivity, modulus of elasticity and drying shrinkage. A study of the behaviours of foamed concrete at varying dry densities for the different characteristics was undertaken. Results indicate that as the dry density increases, the engineering properties increase though at different rates for the 7-day Compressive strength, Thermal conductivity, and Modulus of elasticity. The drying shrinkage decreases as the dry density increases. A comparative study of the 7-day Compressive strength and Modulus of elasticity show that they both follow the same trend over the varying dry density except at a dry density of 1200 kg/m3. A comparative study of the thermal conductivity and the percent drying shrinkage indicate that the thermal conductivity is inversely proportional to the percent drying shrinkage. Economics and other considerations together with its multipurpose applications of foamed concrete can open up business opportunities in Africa and sustainability. This can also help in providing needed funds for infrastructural development.

Study of Foamed Concrete from Activated Ash/Slag Blended Cement

2010 ◽  
Vol 160-162 ◽  
pp. 821-826 ◽  
Author(s):  
Feng Qing Zhao ◽  
Jun Qin Liu ◽  
Qian Li ◽  
Hao Li
Keyword(s):  
Thermal Conductivity ◽  
Fly Ash ◽  
Blended Cement ◽  
Drying Shrinkage ◽  
Curing Process ◽  
Low Carbon ◽  
Freezing And Thawing ◽  
Foaming Agent ◽  
Curing Conditions ◽  
Foamed Concrete

An ecotype of foamed concrete was prepared from activated fly ash/slag blended cement, a kind of low carbon cement, through physical foaming and hydrothermal curing process. The optimized material proportion and curing conditions were obtained with the aid of orthogonal array technique: activated fly ash/slag blended cement-600 kg and foaming agent-1kg for per cubic meter formed concrete, curing at 60°C for 6 hours. The density and compressive strength of the foamed concrete prepared in this method were 644kg/m3 and 4.5MP respectively, and with lower drying shrinkage and thermal conductivity, good freezing and thawing characteristics.

scholarly journals Fibre-Reinforced Foamed Concretes: A Review

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4323 ◽  
Author(s):  
Mugahed Amran ◽  
Roman Fediuk ◽  
Nikolai Vatin ◽  
Yeong Huei Lee ◽  
Gunasekaran Murali ◽  
...  
Keyword(s):  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Sound Insulation ◽  
Plastic State ◽  
High Porosity ◽  
Load Bearing ◽  
Foaming Agents ◽  
Pozzolanic Material ◽  
Aramid Fibres ◽  
Foamed Concrete

Foamed concrete (FC) is a high-quality building material with densities from 300 to 1850 kg/m3, which can have potential use in civil engineering, both as insulation from heat and sound, and for load-bearing structures. However, due to the nature of the cement material and its high porosity, FC is very weak in withstanding tensile loads; therefore, it often cracks in a plastic state, during shrinkage while drying, and also in a solid state. This paper is the first comprehensive review of the use of man-made and natural fibres to produce fibre-reinforced foamed concrete (FRFC). For this purpose, various foaming agents, fibres and other components that can serve as a basis for FRFC are reviewed and discussed in detail. Several factors have been found to affect the mechanical properties of FRFC, namely: fresh and hardened densities, particle size distribution, percentage of pozzolanic material used and volume of chemical foam agent. It was found that the rheological properties of the FRFC mix are influenced by the properties of both fibres and foam; therefore, it is necessary to apply an additional dosage of a foam agent to enhance the adhesion and cohesion between the foam agent and the cementitious filler in comparison with materials without fibres. Various types of fibres allow the reduction of by autogenous shrinkage a factor of 1.2–1.8 and drying shrinkage by a factor of 1.3–1.8. Incorporation of fibres leads to only a slight increase in the compressive strength of foamed concrete; however, it can significantly improve the flexural strength (up to 4 times), tensile strength (up to 3 times) and impact strength (up to 6 times). At the same time, the addition of fibres leads to practically no change in the heat and sound insulation characteristics of foamed concrete and this is basically depended on the type of fibres used such as Nylon and aramid fibres. Thus, FRFC having the presented set of properties has applications in various areas of construction, both in the construction of load-bearing and enclosing structures.

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