scholarly journals Properties and Internal Curing of Concrete Containing Recycled Autoclaved Aerated Lightweight Concrete as Aggregate

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Teewara Suwan ◽  
Pitiwat Wattanachai
Keyword(s):  
Compressive Strength ◽  
Lightweight Concrete ◽  
Value Added ◽  
Aggregate Size ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Green Technology ◽  
Internal Curing ◽  
Low Carbon ◽  
Mix Proportion

Global warming is a vital issue addressed to every sector worldwide, including the construction industry. To achieve the concept of green technology, many attempts have been carried out to develop low-carbon footprint products. In the construction sector, Autoclaved Aerated Concrete (AAC) has become more popular and been manufactured to meet the construction demand. However, errors from manufacturing process accounted for approximately 3 to 5% of the AAC production. The development of AAC waste as lightweight aggregate in concrete is one of the potential approaches which was extendedly studied in this paper. The results showed that the compressive strength of AAC-LWA concrete was decreased with an increase in volume and coarse size. The optimum mix proportion was the AAC aggregate size of 1/2′′ to 3/8′′ with 20 to 40% replacement to normal weight aggregate. Internal curing by AAC-LWA was also observed and found to provide sufficient water inside the specimens, leading to an achievement in higher compressive strength. The main goal of this study is not only utilising unwanted wastes from industry (recycling of waste materials) but also building up a new knowledge of using AAC-LWA as an internal curing agent as well as the production of value-added lightweight concrete products.

scholarly journals Efficiency factor and modulus of elasticity of lightweight concrete with expanded clay aggregate

2010 ◽  
Vol 3 (2) ◽  
pp. 195-204 ◽  
Author(s):  
W.G Moravia ◽  
A. G. Gumieri ◽  
W. L. Vasconcelos
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Large Scale ◽  
Lightweight Concrete ◽  
Weight Ratio ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Empirical Methods ◽  
Normal Weight Concrete

Nowadays lightweight concrete is used on a large scale for structural purposes and to reduce the self-weight of structures. Specific grav- ity, compressive strength, strength/weight ratio and modulus of elasticity are important factors in the mechanical behavior of structures. This work studies these properties in lightweight aggregate concrete (LWAC) and normal-weight concrete (NWC), comparing them. Spe- cific gravity was evaluated in the fresh and hardened states. Four mixture proportions were adopted to evaluate compressive strength. For each proposed mixture proportion of the two concretes, cylindrical specimens were molded and tested at ages of 3, 7 and 28 days. The modulus of elasticity of the NWC and LWAC was analyzed by static, dynamic and empirical methods. The results show a larger strength/ weight ratio for LWAC, although this concrete presented lower compressive strength.

scholarly journals The influence of OPC and PPC on compressive strength of ALWA concrete

2018 ◽  
Vol 195 ◽  
pp. 01021
Author(s):  
Fedya Diajeng Aryani ◽  
Tavio ◽  
I Gusti Putu Raka ◽  
Puryanto
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Structural Members ◽  
Concrete Composition ◽  
Normal Weight Concrete ◽  
To Come ◽  
Seismic Forces

Lightweight concrete is one of the options used in construction in lieu of the traditional normal-weight concrete. Due to its lightweight, it provides lighter structural members and thus, it reduces the total weight of the structures. The reduction in weight resulting in the reduction of the seismic forces since its density is less than 1840 kg/m3. Among all of the concrete constituents, coarse aggregate takes the highest portion of the concrete composition. To produce the lightweight characteristics, it requires innovation on the coarse aggregate to come up with low density of concrete. One possible way is to introduce the use of the artificial lightweight aggregate (ALWA). This study proposes the use of polystyrene as the main ingredient to form the ALWA. The ALWA concrete in the study also used two types of Portland cements, i.e. OPC and PPC. The ALWA introduced in the concrete comprises various percentages, namely 0%, 15%, 50%, and 100% replacement to the coarse aggregate by volume. From the results of the study, it can be found that the compressive strength and the modulus of elasticity of concrete decreased with the increase of the percentage of the ALWA used to replace the natural coarse aggregate.

COMPRESSIVE STRENGTH EVALUATION OF LIGHTWEIGHT CONCRETE WITH EXPANDED GLASS AGGREGATE BY ULTRASONIC PULSE VELOCITY METHOD

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Christopher Collins ◽  
Saman Hedjazi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Normal Weight ◽  
Unit Weight ◽  
Normal Weight Concrete

In the present study, a non-destructive testing method was utilized to assess the mechanical properties of lightweight and normal-weight concrete specimens. The experiment program consisted of more than a hundred concrete specimens with the unit weight ranging from around 850 to 2250 kg/m3. Compressive strength tests were performed at the age of seven and twenty eight days. Ultrasonic Pulse Velocity (UPV) was the NDT that was implemented in this study to investigate the significance of the correlation between UPV and compressive strength of lightweight concrete specimens. Water to cement ratio (w/c), mix designs, aggregate volume, and the amount of normal weight coarse and fine aggregates replaced with lightweight aggregate, are the variables in this work. The lightweight aggregate used in this study, Poraver®, is a product of recycled glass materials. Furthermore, the validity of the current prediction methods in the literature was investigated including comparison between this study and an available expression in the literature on similar materials, for calculation of mechanical properties of lightweight concrete based on pulse velocity. It was observed that the recently developed empirical equation would better predict the compressive strength of lightweight concrete specimens in terms of the pulse velocity.

scholarly journals The Structural Characteristics of Lightweight Aggregate Concrete Beams

2019 ◽  
Vol 27 (2) ◽  
pp. 64-73
Author(s):  
Sajjad abdulameer Badar ◽  
Laith Shakir Rasheed ◽  
Shakir Ahmed Salih
Keyword(s):  
Compressive Strength ◽  
Ultimate Load ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Dry Density ◽  
Aggregate Concrete ◽  
Clay Bricks

This paper aims to investigate the structural behavior of reinforced lightweight concrete beams. Attapulgite aggregate and crushed clay brick aggregate were used as coarse lightweight aggregate to produce structural lightweight aggregate concrete with 25 Mpa and 43.6 Mpa cube compressive strength and 1805 Kg/m3 and 1977 Kg/m3 oven dry density respectively. The result of reinforced lightweight concrete beams compared with reinforced normal weight concrete beams, which have 50.5 Mpa cylinder compressive strength and 2317 Kg/m3 oven dry density. For each type of concrete two reinforced concrete beams with (1200 mm length × 180 mm height × 140 mm width), one of them tested under symmetrical two-points load STPL (a/d = 2.2) and another one tested under one-point load OPL (a/d=3.3) at 28 days. The experimental program shows that a structural lightweight aggregate concrete can be produced by using Attapulgite aggregate with 25 MPa cube compressive strength and 1805 Kg/m3 oven dry density and by using crushed clay brick aggregate with 43.6 MPa cube compressive strength and 1977 Kg/m3 oven dry density. The weight of Attapulgite aggregate concrete and crushed clay bricks aggregate concrete beam specimens were lower than normal weight aggregate concrete beams by about 20.56% and 13.65% respectively at 28 days.  As for the ultimate load capacities of beam specimens, the ultimate load of Attapulgite aggregate concrete beams tested under STPL were lower than that of crushed clay bricks aggregate concrete beams and normal weight aggregate concrete beams by about 4.85% and 5% respectively. While the ultimate load capacities of reinforced Attapulgite concrete beams tested under OPL were lower than that of reinforced crushed clay bricks aggregate concrete beams and reinforced normal weight aggregate concrete beams by about 10.3% and 10.5% respectively. Finally, Attapulgite aggregate concrete and crushed clay bricks aggregate concrete showed ductility and toughness less than that of Normal weight aggregate concrete.

Evaluation of Silica Fume Effect on Compressive Strength of Structural Lightweight Concrete Containing LECA as Lightweight Aggregate

2012 ◽  
Vol 626 ◽  
pp. 344-349 ◽  
Author(s):  
Maryam Mortazavi ◽  
Mojtaba Majlessi
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Considerable Increase ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Mix Design ◽  
Strength Gain ◽  
Experimental Phase ◽  
Normal Weight Concrete

The purpose of this paper is to evaluate the effect of silica fume on compressive strength of structural lightweight concrete, containing saturated LECA (Light Expanded Clay Aggregate) as lightweight aggregate (LWA). In experimental phase of study 120 cubic specimens (10*10*10) were made and cured. For every mix design, different cement percentages were replaced with silica fume, containing same amount of saturated LECA. The mixes incorporate 0%, 5%, 10%, 15%, 20%, 25% silica fume. Constant level of Water/Cement ratio (0.37) was considered. For each mix design 20 specimens were prepared and cured for 7, 14, 28, 42 days in standard 20 C water. Also 20 specimens with the same mix design of 0% silica fume as normal weight concrete were prepared and cured to compare the results. For these specimens LECA were replaced with same volume and size of sand. The testing results showed; increasing silica fume causes considerable increase in compressive strength. The rate of strength gain slows down at high percentage of silica fume. Also silica fume leads concrete to get higher initial compressive strength at certain time compared with normal weight concrete.

scholarly journals Self-Consolidating Lightweight Concrete Incorporating Limestone Powder and Fly Ash as Supplementary Cementing Material

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3050 ◽  
Author(s):  
Khan ◽  
Usman ◽  
Rizwan ◽  
Hanif
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Limestone Powder ◽  
Normal Weight Concrete ◽  
Supplementary Cementing Materials ◽  
Fresh State ◽  
Cementing Material

This paper assesses the mechanical and structural behavior of self-consolidating lightweight concrete (SCLWC) incorporating bloated shale aggregate (BSA). BSA was manufactured by expanding shale pellets of varying sizes by heating them up to a temperature of 1200 °C using natural gas as fuel in the rotary kiln. Fly ash (FA) and limestone powder (LSP) were used as supplementary cementing materials (10% replacement of cement, each for LSP and FA) for improved properties of the resulting concrete. The main parameters studied in this experimental study were compressive strength, elastic modulus, and microstructure. The fresh-state properties (Slump flow, V-funnel, J-Ring, and L-box) showed adequate rheological behavior of SCLWC in comparison with self-consolidating normal weight concrete (SCNWC). There was meager (2%–4%) compressive strength reduction of SCLWC. Lightweight aggregate tended to shift concrete behavior from ductile to brittle, causing reduced strain capacity and flexural toughness. FA and LSP addition significantly improved the strength and microstructure at all ages. The study is encouraging for the structural use of lightweight concrete, which could reduce the overall construction cost.

scholarly journals Effect of Aggregate Size on Strength Characteristics of High Strength Lightweight Concrete

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1314
Author(s):  
Hui Wei ◽  
Yang Liu ◽  
Tao Wu ◽  
Xi Liu
Keyword(s):  
Compressive Strength ◽  
Lightweight Concrete ◽  
Aggregate Size ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Medium Size ◽  
Test Results ◽  
Estimation Model ◽  
Strength Tests ◽  
Single Size

Effects of aggregate size on the mechanical properties of lightweight concrete (LC) were investigated. Four gradings of lightweight aggregate (LWA) were designed and used to prepare the specimens for compressive strength, splitting tensile strength, and flexural strength tests. An estimating method for compressive strength of LC was then established. The compressive strength of tested LC was up to 95 MPa at 90-day curing time. The test results suggested that the absence of medium-size particles decreased the compaction of LC, therefore the density and compressive strength were negatively affected. Specimens having single size of aggregate showed lower splitting tensile and flexural strengths than that having three sizes of LWA. The parameters of the estimating model were determined according to the test results, and the compressive strength predictions of estimation model were compared with the results from other literature.

scholarly journals MODIFICATION OF PROPERTIES OF STRUCTURAL LIGHTWEIGHT CONCRETE WITH STEEL FIBRES / LENGVOJO BETONO SAVYBIŲ MODIFIKAVIMAS PLIENINĖMIS FIBROMIS

2011 ◽  
Vol 17 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Lucyna Domagała
Keyword(s):  
Compressive Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Rheological Parameters ◽  
Lightweight Aggregate Concrete ◽  
Significant Deterioration ◽  
Steel Fibres ◽  
Concrete Mixtures ◽  
Weight One

Structural lightweight aggregate concrete (SLWAC) is an alternative building material to normal-weight one, due to its ability to reach a relatively high compressive strength at still significantly lower density. Nevertheless, the application of lightweight aggregate instead of normal-weight one to concrete must result in deterioration of some characteristics of the composite. One of the methods of improving SLWAC properties is incorporation of fibers into concrete. This paper focuses on the influence of steel fibres on modification of properties of structural lightweight concrete with sintered fly ash aggregate. Two different concrete mixtures, producing various levels of matured composite density and compressive strength, were modified with three dosages of fibers: 30, 45 and 60 kg/m3. The applied amounts did not result in significant deterioration of the rheological parameters of concrete mixtures. Despite relatively low volume content of fibres, a considerable increase of flexural and tensile splitting strength was observed. Fibres also improved concrete shrinkage as well as post-peak deformability in uni-axial compression. The effect of steel addition on compressive strength proved to be dependent on specimen type. Nevertheless, it was not as crucial as in the case of the above characteristics. However, the modulus of elasticity of SLWAC was not affected by fibre addition. Santrauka Konstrukcinis su lengvaisiais užpildais betonas (SLWAC) yra normalaus svorio statybinių medžiagų alternatyva, turinti mažesnį tankį ir gebėjimą pasiekti gana didelį gniuždomąjį stiprį. Nepaisant to, lengvieji užpildai, naudojami vietoj normalaus svorio užpildų, realiai gali pabloginti kai kurias kompozito savybes. Vienas iš lengvojo betono SLWAC savybių tobulinimo būdų yra plieninių fibrų įterpimas į betono sudėtį. Šiame darbe aptariamas plieninių fibrų poveikis konstrukcinio lengvojo betono su lakiaisiais pelenais savybėms. Tikslui pasiekti buvo parinktos pagal tankį ir gniuždomąjį stiprį dvi skirtingos betono sudėtys su skirtingais (30, 45 ir 60 kg/m3) plieninių fibrų tankiais. Paruošti bandiniai buvo naudoti gniuždomajam stipriui ir kitoms savybėms nustatyti. Tyrimų rezultatai parodė, kad plieninių fibrų priedas nepablogino reologinių betono mišinio rodiklių. Nepaisant palyginti mažo fibrų kiekio, labai padidėjo bandinių lenkiamasis ir tempiamasis stipris. Fibros taip pat pagerino deformacines betono savybes. Gauto kompozito gniuždomasis stipris iš dalies priklausė nuo naudojamų plieninių fibrų charakteristikų. Tačiau plieninių fibrų priedas nepakeitė SLWAC tamprumo modulio.

scholarly journals Behavior of structural lightweight concrete produced with expanded clay aggregate and after exposure to high temperatures

2021 ◽  
Author(s):  
Rita Nemes ◽  
Mohammed A. Abed ◽  
Ahmed M. Seyam ◽  
Éva Lublóy
Keyword(s):  
Compressive Strength ◽  
High Temperatures ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Residual Compressive Strength ◽  
Concrete Mixtures ◽  
Temperature Exposure ◽  
Compaction Method ◽  
Do So

AbstractThe residual compressive strength of eight lightweight concrete mixtures containing three commercial grading (Liapor HD 5 N, Liapor HD 7 N, and Liapor 8F) of coarse lightweight aggregate (LWA) were determined after to expose at high temperatures. Eight mixes were produced, two by normal weight aggregate and the rest by different types of LWA. The produced concrete was analyzed after high temperature exposure and the effect of using LWA, the type of LWA, and compaction method was studied. To do so, visual inspection, residual compressive strength, crack pattern, spalling, and thermoanalytical analysis were conducted. Generally, it could be concluded that concrete formulations with LWA behave more advantageous up to 500 °C, compared to those with quartz gravel aggregates. Moreover, this study found that an ideal type of LWA to produce structural concrete was Liapor HD 5 N, which was used for producing the mixes L1 and L3.

scholarly journals Compressive Strength of Steel-Fiber Concrete with Artificial Lightweight Aggregate (ALWA)

2018 ◽  
Vol 4 (9) ◽  
pp. 2011 ◽  
Author(s):  
Meity Wulandari ◽  
Tavio Tavio ◽  
I G. P. Raka ◽  
Puryanto Puryanto
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
Aggregate Size ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregates ◽  
Normal Weight Concrete ◽  
Coarse Aggregates ◽  
Steel Fiber Concrete

In the last decade, there have been many innovations developed to replace the aggregate as material for concrete, particularly the coarse aggregate using the artificial lightweight aggregates a.k.a. ALWA. In the study, the main ingredient used to develop the artificial lightweight aggregates is the styrofoam. Styrofoam has a lightweight characteristic so that it can reduce the density of the concrete. If the density of the concrete can be lighter than the normal-weight concrete then the overall weight of the structure of a building will also be lighter. Thus, the shear force due to the earthquake will also be smaller so that the safety of the building becomes better. The styrofoam used was dissolved with the acetone solution and formed into granules in which the size resembled the coarse aggregate size of about 10 to 20 mm. The styrofoam which has been formed then dried up so that the texture becomes hard. In addition, steel fiber was also used as an added ingredient in concrete mixtures so that the concrete was highly resistant against cracking and was expected to increase the compressive strength of the concrete. ALWA compositions used to replace coarse aggregates were 0%, 15%, 50%, and 100%. While the composition of steel fiber used was 0%, 0.75%, and 1.5% of the total volume of the cylinder. The type of steel fiber used was hooked-end steel fiber with the diameter and the length of 0.8 mm and 60 mm, respectively. The results showed that the concrete with 15% styrofoam ALWA and 1.5% of steel fiber were able to produce optimum compressive strength by 28.5 MPa and the modulus of elasticity by 23,495 MPa. In addition, the use of Styrofoam ALWA as a substitution to the coarse aggregate can reduce the density of concrete as much as 5 to 35%.

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