scholarly journals Investigation of Physical Characteristics of Non-Structural Lightweight Aggregate Blocks

Author(s):  
Hamid Reza Ashrafi ◽  
Marzieh Sadat Moayyeri ◽  
Peyman Beiranvand

Today, the style of light construction materials used in building is one of the most important factors in reducing building's dead load and better performance of the structures in the earthquake. One of the ways to reduce the structure weight is to use lightweight blocks instead of using traditional materials. The main purpose of this research is to compare density, compressive strength and water absorption volume of non-load-bearing lightweight blocks made of natural and artificial lightweight aggregates. Scoria lightweight aggregates of Sanandaj, Ghorveh mine, pumice in Tabriz, Bostanabad mine, and Leca in Leca enterprise have been used to make the samples. Given the importance of the materials used, grading of coarse-grained materials has been conducted based on the standard of 7657 and grading of fine materials have been conducted based on the standard of 302.The experiments' results show that Scoria blocks due to hard texture, and high mechanical resistance of their lightweight aggregates, have had higher compressive strength, and density and lower water absorption volume compared to pumice and Lika lightweight aggregate blocks. Pumice blocks despite having desirable compressive strength and lower density compared to the two other blocks have higher water absorption volume, and do not meet the standard conditions. This same factor causes it faces with less interest. Among these Lika blocks with density of 1151.94 (kg per cubic meter) below 2000 kilograms per cubic meter of Iran density standard of 7782 (28-day compressive strength of 2.57 MPa), higher than 2.5 MPa of Iran compressive strength standard of 7782 (and water absorption volume of 282.92 kg per cubic meter) below 288 kilograms per cubic meter of Iran water absorption volume standard of 7782 (as a non-load-bearing lightweight block) have been diagnosed desirable.

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 198
Author(s):  
Lucyna Domagała ◽  
Agnieszka Podolska

The impregnation of lightweight aggregate (LWA) is an alternative method to its pre-moistening, which is used to limit the loss of fresh concrete workability due to the aggregate’s ability to absorb a great amount of mixing water. The aim of this study was to access the effectiveness, by pre-coating LWAs with cement paste, in modifying the properties of concrete composites. Two types of lightweight aggregates (Lytag and Leca) characterized with a relatively open-structure shell were selected. The other changeable parameters taken into consideration in this research were: LWA size, initial moisture of aggregate before the impregnation process and type of cement paste applied as an impregnant. Sixteen concretes prepared with pre-moistened and pre-coated lightweight aggregates were subject to a density test in different moisture conditions, a water absorption test and a compressive strength test. On the one hand, the pre-coating of LWAs with cement paste resulted in a relatively slight increase in concrete density (by up to 19%) compared to the pre-moistening of LWAs. On the other hand, it caused a very significant reduction (by up to 52%) in the composite’s water absorption and an incomparably greater growth (by up to 107%) in compressive strength. The most crucial factors determining the effectiveness of impregnation of LWAs with cement pastes in improvement of composite properties were the aggregate type and its size. The composition of impregnating slurry and the initial moisture content of LWA before pre-coating also mattered.


Author(s):  
Mehdi Torabi-Kaveh ◽  
Mohammadreza Moshrefyfar ◽  
Jafar Zarezadeh ◽  
Seyed Mohammad Ali Moosavizadeh

This study examined the potential of some shales obtained from different formations in Yazd province to produce Lightweight aggregates (LWAs) as natural materials and without the application of additives. Before heating the samples, the materials' usefulness for producing lightweight aggregates was examined by detecting the elemental and mineralogical composition of the shale samples. The presence of aluminosilicates and flux content confirmed and met the required conditions discussed by Riley's theory for the bloating process. Among the studied shale samples, Kharanagh shale samples of Kh1 and Kh2 were found as the most suitable materials to produce highly porous, light and mechanically durable aggregates after heating at the optimum temperature of 1200°C for a heating duration of 10min. The produced LWAs showed low density (for sample Kh1 equal to 0.7gr/cm3 which is close to the commercial LECA), low water absorption (quick water absorption indices of 5.35% and 5.48% for samples Kh1 and Kh2, respectively, which are less than one-third of LECA water absorption), porous microstructure (porous like LECA but with smaller pore size), and good mechanical properties (with aggregate impact and aggregate crushing values less than that of LECA and in the range of values suggested for construction aims). Finally, it was revealed that the produced LWAs have suitable microstructure, physical and mechanical properties, comparable with the commercial ones, which approve their potential for use as construction materials in lightweight concrete and road surface constructions.


2018 ◽  
Vol 7 (2.29) ◽  
pp. 927 ◽  
Author(s):  
Bishir Kado ◽  
Shahrin Mohammad ◽  
Yeong Huei Lee ◽  
Poi Ngian Shek ◽  
Mariyana Aida Ab Kadir

Lightweight construction is aimed to achieve a sustainable feature by reducing transportation frequency and construction materials usage during construction phase. Lightweight precast concrete may serve an alternative for the lightweight construction. There are rarely application can be found for structural members as lightweight panels always to be used for secondary or non-load bearing members. This paper presents an experimental study on properties (compressive strength, splitting tensile strength, water absorption) of lightweight foamed concrete (LFC) at two different curing methods. LFC with densities of 1500, 1700, and 1800 kg/m3, cement-sand ratio of 2:1 and water-cement ratio of 0.5 were investigated. The results showed LFC can be produced with the properties ofdensity range of 1500 to 1800 kg/m3 and corresponding compressive strength of 10 to 39 MPa. The higher the density of LFC, the less the water absorption for all the curing method considered, the highest and the lowest water absorption was 11.3% and 2.0% for 1500 kg/m3 cured in water and 1800 kg/m3 cured in air respectively. Compressive strength of LFC increases with age and density while water cured LFC has high compressive strength. Splitting tensile strength increases with density of LFC, but air cured LFC has more splitting tensile strength than water cured of the same density. The highest splitting tensile strength recorded was 3.92 MPa for 1800 kg/m3 cured in air, which was about 16% of its compressive strength at 28 days of curing age. These properties are important and can be applied to LFC precast structural members with air or water curing method which have less references for LFC in structural usage.  


2016 ◽  
Vol 7 (5) ◽  
pp. 546-550
Author(s):  
Aurelijus Daugėla ◽  
Džigita Nagrockienė ◽  
Laurynas Zarauskas

Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.


Author(s):  
K. O. Oriola

The evaluation of agro-industrial by-products as alternative construction materials is becoming more significant as the demand for environmentally friendly construction materials increases. In this study, the workability and compressive strength of concrete produced by combining Palm Kernel Shell (PKS) and Rice Husk Ash (RHA) was investigated. Concrete mixes using a fixed content of 15% RHA as replacement for cement and 20, 40, 60, 80 and 100% PKS as replacement for crushed granite by volume with the mix ratios of 1:1½:3, 1:2:4 and 1:3:6 were produced. The water-to-cement ratios of 0.5, 0.6 and 0.7 were used for the respective mix ratios. Concrete without PKS and RHA served as control mix. The fresh concrete workability was evaluated through slump test. The concrete hardened properties determined were the density and compressive strength. The results indicated that the workability and density of PKSC were lower than control concrete, and they decreased as the PKS content in each mix ratio was increased. The compressive strength of concrete at 90 days decreased from 27.8-13.1 N/mm2, 23.8-8.9 N/mm2and 20.6-7.6 for 1:1½:3, 1:2:4 and 1:3:6, respectively as the substitution level of PKS increased from 0-100%. However, the compressive strength of concrete increased with curing age and the gain in strength of concrete containing RHA and PKSC were higher than the control at the later age. The concrete containing 15% RHA with up to 40% PKS for 1:1½:3 and 20% PKS for 1:2:4 mix ratios satisfied the minimum strength requirements for structural lightweight aggregate concrete (SLWAC) stipulated by the relevant standards. It can be concluded that the addition of 15% RHA is effective in improving the strength properties of PKSC for eco-friendly SLWAC production..


2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.


2014 ◽  
Vol 711 ◽  
pp. 166-169
Author(s):  
Jing Li ◽  
Guo Zhong Li

Polystyrene granules (EPS) for lightweight aggregate and cement for cementing material, while adding a variety of additives, were used to prepare cement-based composite thermal insulation materials by the method of vibration molding. The effects of different waterproof agent on water absorption and strength of cement-based composite thermal insulation materials were studied contrastively by adding emulsified stearic acid and emulsified composite waterproofing agent, and the related mechanisms were analyzed. Results showed that the waterproofing effect and strengthen effect of emulsified composite waterproofing agent is superior to emulsified stearic acid, when the content of emulsified stearic acid and emulsified composite waterproofing agent are 5% and 5%, respectively, the 2h, 24h water absorption of samples are 20.59%, 47.64% and 15.53%, 34.53%, the flexural and compressive strength of samples are 0.32MPa, 0.42MPa and 0.35MPa, 0.47MPa.


2020 ◽  
Vol 853 ◽  
pp. 120-125
Author(s):  
Airvin John C. Palacio ◽  
Nioro G. Furiscal ◽  
Katrina Mae L. Abalos ◽  
Dioven Angelo A. Alferez ◽  
Edmer A. Bade ◽  
...  

Waste disposal is one of the issues that plague the society. Philippines is an agricultural country due to its strategic location in the tropics. Because of this nature, the agriculture sector tends to produce a huge amount of waste that if not disposed properly could pose a threat to the society and to the environment. With the advancement of technology, it has been a challenge for researchers to improve the quality of construction materials that is used in the industry. Studies have been performed on the possibilities of incorporating agricultural wastes to various construction materials as a form of waste diversion. In order to address the problem with agricultural wastes as well as to improve the property of construction materials, a study on coconut waste and eggshell waste was conducted as a constituent in concrete brick production. In this study, the density, compressive strength as well as the water absorption of concrete bricks with coconut charcoal powder (CCP) and eggshell powder (ESP) as replacement for fine aggregates and cement was conducted. Different mix ratios (0%, 2.5%, 5%, 10% CCP with a constant value of 5% ESP in each mix ratio) were carried out and the results were compared to a control sample. From the results of the density test, the concrete bricks with 5% CCP and 5% ESP was the lightest at a density of 1678.184 kg/m3, it also showed the least water absorption at 8.58% and exhibited the highest compressive strength at 17.5 MPa.


2015 ◽  
Vol 754-755 ◽  
pp. 290-295 ◽  
Author(s):  
Alida Abdullah ◽  
Ku Amirrul Rahman Ku Yin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Mien Van Tran

This study was conducted to compare the mechanical properties of fly ash artificial geopolymer aggregates with natural aggregate (rock) in term of its impact strength, specific gravity and water absorption.The raw materials used were fly ash, sodium hydroxide, sodium silicate and natural aggregate. After the artificial geopolymer aggregate has been produced, its water absorption, specific gravity and aggregate impact test has been done. All results obtained were compared to natural aggregate. The result shows that the fly ash geopolymer aggregate are lighter than natural aggregate in term of its specific gravity. The impact value for fly ash artificial geopolymer aggregate slightly high compared to natural aggregate while it has high water absorption value compared to natural aggregate. As conclusion, the fly ash artificial geopolymer aggregate can be used as one of the construction materials in concrete as an alternative for coarse aggregate besides natural aggregate with more lightweight properties.


Author(s):  
Leopold Mbereyaho ◽  
Jean de Dieu Mutabaruka ◽  
Abaho G. Gershome ◽  
Armel Ineza ◽  
Ezra Ngirabatware

The construction industry is one of the rapidly growing and the cost analysis suggests that the materials cost is constantly increasing. The continuous extraction of aggregates intensively used in the field is negatively acting to the environment. Therefore research in construction materials should focus not only on discovering new alternative materials but also in appreciating the quality of those locally available for their better application. This research aimed at evaluating the performance of bamboo and mud bricks as two available local building materials, especially with regards not only to their strength but also to new performance concepts which are affordability, energy efficiency and environment friendly aspects. The study comprised mainly of laboratory tests of used materials and cost estimation analysis. Study results established that the considered bamboo and mud bricks, made in ordinary soils and reinforced by sisal fibers were reusable, environment friendly materials and energy efficient, with the bamboo showing the thermal conductivity equal to 0.1496 W/mK. Regarding the compressive strength, reinforced mud bricks with sisal fibers showed an increased value from 1.75 MPA to 4.29MPA, what was in line with related previous studies. The average compressive strength of the studied Arundinaria Alpine bamboo was established at 133,7MPA, while its tensile strength was 88.16MPA and these values were reasonable with comparison to other conventional materials. It is recommended that further research in checking the performance of other types of bamboo as well as about new construction technologies be undertaken in order to enhance the service life of both bamboo and mud bricks.Keywords: Affordability, Bamboo, Conventional concrete, Materials strength, Mud reinforced bricks, Sustainability


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