Mixed Proportion Design of Lightweight Concrete Using the Sludge Kilned Coarse Aggregate from Reservoir

2012 ◽  
Vol 430-432 ◽  
pp. 602-608 ◽  
Author(s):  
Hsi Chi Yang ◽  
Jung Pin Wang ◽  
Jiun Wei Wu
Keyword(s):  
Water Consumption ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Quality Characteristics ◽  
Unit Weight ◽  
Control Factors ◽  
Operational Life ◽  
Binder Ratio ◽  
Water Binder Ratio

The sludge dramatically causes the water pollution and storage reduction of a reservoir, threatening its functionality and operational life span. One strategy is to add sludge into lightweight concrete, thus, recycling the sludge and making it one of the valuable natural resources. This study intends to use the Design of Experiment (DOE) and Taguchi Method to ensure the stability of quality and to reduce the production cost of lightweight concrete using the sludge kilned coarse aggregate from the Shihmen reservoir in Taiwan. Based on literature reviews as well as past experimental results, the research selects four control factors including lightweight aggregate unit weight, water content, water-binder ratio (W/B), and interactions among these factors. By using Analysis of Variance (ANOVA), this study discusses the significant degree of these control factors and their interactions, affecting the quality characteristics of lightweight concrete such as compressive strength, ultrasonic wave, and electric resistance at different ages. The significant levels and contribution ratios from each ANOVA analysis are placed in a Cross Table to obtain the overall evaluation, giving the optimal mix proportions. On the basis of the results, the optimal parameter setting are: the unit weight of lightweight aggregate at 0.378 g/cm3, the water consumption at 160 kg/m3, and the water-binder ratio at 0.28 for the 14 and 28-day age lightweight aggregate concrete, and the unit weight of lightweight aggregate at 0.378 g/cm3, the water consumption at 140 kg/m3, and the water-binder ratio at 0.28 for the 91-day age. Furthermore, considering the mean and variance, the research find out the optimal design according to the combination of ages and quality characteristics using the Type III Signal to Noise Ratio of Taguchi’s nominal-is-the-best quality characteristics. The obtained result includes the unit weight of lightweight aggregate at 0.378 g/cm3, the water consumption at 160 kg/m3, and the water-binder ratio at 0.28.

scholarly journals Influence of Coarse Aggregate Gradation on the Mechnical Properties of Concrete, Part I: No-Fines Concrete

2019 ◽  
Vol 9 (5) ◽  
pp. 4612-4615 ◽  
Author(s):  
Z. A. Tunio ◽  
F. U. R. Abro ◽  
T. Ali ◽  
A. S. Buller ◽  
M. A. Abbasi
Keyword(s):  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Fine Sand ◽  
Minimum Size ◽  
Unit Weight ◽  
Lightweight Aggregate Concrete ◽  
Total Load ◽  
Aggregate Gradation ◽  
Coarse Aggregates

It is well-accepted fact that in concrete construction, the self-weight of the structure is a major part of its total load. Reduction in the unit weight of the concrete results in many advantages. The structural lightweight aggregate concrete (LWAC) of adequate strength is now very common in use. In frame structures, the partition walls are free of any loading, where the construction of these non-structural elements with lightweight concrete of low strength would lead to the subsequent reduction of the overall weight of the structure. No-fines concrete is one of the forms of lightweight concrete and it is porous in nature. It can be manufactured similarly as normal concrete but with only coarse aggregates and without the sand. Thus, it has only two main ingredients; the coarse aggregates and the cement. The coarse aggregates are coated with a thin cement paste layer without fine sand. This is a detailed experimental study carried on NFC with fixed cement to the aggregate proportion of 1:6 with w/c 0.40 ratio. In this study, coarse aggregate of  various gradations (7-4.75) mm, (10-4.75) mm, (10-7) mm, (13-4.74) mm, (10-7) mm, (13-4.75) mm, (13-10) mm, (13-7) mm, (20-4.75) mm, (20-7) mm, (20-10) mm, (20-13) mm, are used, where prefix and suffix show the maximum and minimum size of the aggregate. The cube and cylinder specimens of standard sizes are cast to determine the compressive strength and splitting tensile and the specimens are cured in water up to the age of testing (28 days).

Properties of Lightweight Concrete Masonry Units Made from Lightweight Aggregates

2010 ◽  
Vol 150-151 ◽  
pp. 1588-1594
Author(s):  
Chao Wei Tang ◽  
Kuo Haung Fan ◽  
Wen Po Tsai ◽  
How Ji Chen
Keyword(s):  
High Performance ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Filling Ratio ◽  
National Standards ◽  
Unit Weight ◽  
Concrete Masonry ◽  
Research Findings

In the paper the properties of concrete masonry unit (CMU) made from sedimentary lightweight aggregate (LWA) were investigated. The main variables include water to cementitious material ratio (W/CM), filling ratio of paste or mortar in voids between coarse aggregate particles (Fv), filling ratio of sand in mortar (Fm), and cement replacement level by slag (Sc). Test results of representative CMU specimens show that unit weight ranged from 1585 to 1743 kg/m3, which was 30-25% lower than that for a normal weight CMU (2300 kg/m3); compressive strengths ranged from 8.4 to 18.7 MPa; water absorption was found to vary between 0.05 to 0.13 g/cm3; and thermal conductivity ranged from 0.27 to 0.41 W/mK. The research findings demonstrate that the use of sedimentary LWA as coarse aggregate in various concrete mixtures could produce high performance lightweight CMU, which comply with the requirements of Chinese National Standards (CNS) standards.

scholarly journals Sustainable Green Lightweight Concrete Containing Plastic-Based Green Lightweight Aggregate

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3304
Author(s):  
Fahad K. Alqahtani
Keyword(s):  
Natural Resources ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Plastic Waste ◽  
Unit Weight ◽  
Lightweight Aggregate Concrete ◽  
Dry Density ◽  
Study Results

Nowadays the environment and its natural resources face many issues, related to the depletion of natural resources beside the increase in environmental pollution resulted from uncontrolled plastic waste disposal. Therefore, it is important to find effective and feasible solutions to utilize these wastes, such as using them to produce environmentally friendly green concrete. In this study, plastic-based green lightweight aggregates (PGLAs) containing PET plastic waste and by product additives were developed, and their subsequent physical and mechanical properties were compared with those of reference aggregates. Then, green lightweight aggregate concrete mixes (GLACs) were produced at 100% replacement of normal weight and lightweight coarse aggregate with developed PGLAs; and their fresh, hardened, microscopic and durability-related properties were compared to those of control mixes. Study results revealed that the unit weight of PGLAs were 21% to 29% less than that of normal coarse aggregate. Additionally, PGLAs had low water absorption that varied between 1.2% and 1.6%. The developed aggregates had 45% higher strength compared to that of lightweight coarse aggregate. Study results confirmed that structural green lightweight aggregate concretes (GLACs), that satisfied the dry density, compressive and splitting tensile strength requirements specified in ASTM C330, were feasibly produced. Finally, GLACs had low-to-moderate chloride penetration in accordance with ASTM C1202, thus it can be used in those areas exposed to the risk of chloride attack.

scholarly journals The Rapid Chloride Migration Test in Assessing the Chloride Penetration Resistance of Normal and Lightweight Concrete

2021 ◽  
Vol 11 (16) ◽  
pp. 7251
Author(s):  
Jorge Pontes ◽  
José Alexandre Bogas ◽  
Sofia Real ◽  
André Silva
Keyword(s):  
Lightweight Concrete ◽  
Chloride Transport ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Migration Test ◽  
Simple Method ◽  
Chloride Migration ◽  
Binder Ratio ◽  
Chloride Penetration Resistance ◽  
Water Binder Ratio

Chloride-induced corrosion has been one of the main causes of reinforced concrete deterioration. One of the most used methods in assessing the chloride penetration resistance of concrete is the rapid chloride migration test (RCMT). This is an expeditious and simple method but may not be representative of the chloride transport behaviour of concrete in real environment. Other methods, like immersion (IT) and wetting–drying tests (WDT), allow for a more accurate approach to reality, but are laborious and very time-consuming. This paper aims to analyse the capacity of RCMT in assessing the chloride penetration resistance of common concrete produced with different types of aggregate (normal and lightweight) and paste composition (variable type of binder and water/binder ratio). To this end, the RCMT results were compared with those obtained from the same concretes under long-term IT and WDT. A reasonable correlation between the RCMT and diffusion tests was found, when slow-reactive supplementary materials or porous lightweight aggregates surrounded by weak pastes were not considered. A poorer correlation was found when concrete was exposed under wetting–drying conditions. Nevertheless, the RCMT was able to sort concretes in different classes of chloride penetration resistance under distinct exposure conditions, regardless of the type of aggregate and water/binder ratio.

Analysis of the Durability of Lightweight Concrete Protected by an Acrylic Layer in an Aggressive Acid Environment

2015 ◽  
Vol 668 ◽  
pp. 255-259
Author(s):  
Carmen Couto Ribeiro ◽  
Felipe de Souza Abreu ◽  
Tadeu Starling ◽  
Pedro José Lopes Neto ◽  
Joana Darc Silva Pinto
Keyword(s):  
Visual Inspection ◽  
Lightweight Concrete ◽  
Specific Mass ◽  
Adherence Level ◽  
Good Adherence ◽  
Adverse Conditions ◽  
Aggressive Environment ◽  
Binder Ratio ◽  
Acid Environment ◽  
Water Binder Ratio

When exposed to adverse conditions the concrete must be protected so as to maintain absorption at acceptable levels. This paper presents the assessment of a lightweight expanded clay concrete protected by an acrylic layer exposed to an aggressive environment. The specimens were prepared with 370kg/m3 of cement and the water-binder ratio of 0.50 corresponds to the value established in NBR 6118 types for concrete subjected to highly aggressive environments. The concrete produced presented specific mass of 1,600kg/m3, dry consistency and compressive strength of 25MPa. Visual inspection shows that the protected specimens of lightweight concrete presented a clear reduction of the loss of cohesion of the grout caused by the attack as well as lower water absorption and mass loss. The acrylic layer assessed as a surface protector presented a good adherence level to the substrate and efficiency since it reduced the penetration of the aggressive agent, thus minimizing degradation and increasing durability of the lightweight expanded clay concrete.

scholarly journals Evaluation of Heat Insulation and Surface Resistivity of Mineral Lightweight Aggregate Concrete(MLAC)

2020 ◽  
Vol 10 (21) ◽  
pp. 7871
Author(s):  
Jung-Nan Chang ◽  
Tung-Tsan Chen ◽  
Chang-Chi Hung ◽  
Her-Yung Wang
Keyword(s):  
Heat Insulation ◽  
Lightweight Aggregate ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Unit Weight ◽  
Lightweight Aggregate Concrete ◽  
Control Group ◽  
K Value ◽  
Aggregate Concrete ◽  
Binder Ratio

In this study, the fixed water/binder ratio is 0.40, four mineral admixtures: fly ash (FA), blast furnace slag (BFS), desulphurization slag (DLS), and glass LED powder (GLP), were added to lightweight aggregate concrete (LWAC), replacing 10% or 30% of the cement content, to study their heat insulation efficiency and engineering performance and to compare the economic impact of mineral admixtures on LWAC. In terms of heat insulation, the thermal conductivity (K value) of the controlled sample was 0.484 kcal/(m.h. °C) and the addition of mineral admixtures changed the concrete unit weight and water absorption ratio, thus reducing the K value by 0.41% to 25.71% and improving the heat insulation. As the mineral admixture hydration products and chemical contents differed, the heat insulation of the LWAC varied as well. The study indicated that the heat insulation is the greatest in concrete with the addition of 30% FA, followed by concrete with the addition of 10% GLP. The addition of mineral admixtures is 30%, the resistivity is 72–455% of the control group, and the resistivity of FA and GLP is higher than the control group. The study is indicated that the proper addition of mineral powder material has an apparent effect on increasing heat insulation efficiency.

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.

Proportion Design of Autoclaved Cement Concrete Based on High Strength

2011 ◽  
Vol 391-392 ◽  
pp. 161-164
Author(s):  
Tie Quan Ni ◽  
Chang Jun Ke ◽  
Li Zhang
Keyword(s):  
Coarse Aggregate ◽  
High Strength ◽  
Orthogonal Test ◽  
Mineral Admixture ◽  
Mix Design ◽  
Hydration Reaction ◽  
Cement Concrete ◽  
Binder Ratio ◽  
Four Levels ◽  
Water Binder Ratio

According to the particularity of the autoclaved cement concrete that partial aggregate could participate in hydration reaction in the process of autoclaving, the optimal gradation of coarse aggregate and the optimal slurry aggregate ratio is studied, and the effect of water reducing agent for fluidity of cement paste is also studied. The optimized mix design of autoclaved cement concrete based on high strength (compressive strength and flexural strength) is done by orthogonal test with four factors (water-binder ratio, type of mineral admixture, amount and sand ratio) and four levels.

scholarly journals Self-Compacting Concrete with Recycled Coarse Aggregate and Manufactured Sand

2019 ◽  
Vol 9 (1) ◽  
pp. 3868-3873
Keyword(s):  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Manufactured Sand ◽  
Recycled Coarse Aggregate ◽  
Recycle Coarse Aggregate ◽  
Binder Ratio ◽  
Water Binder Ratio

This article mainly focused on the influence of recycle coarse aggregate and manufactured sand on the properties of self compacting concrete (SCC). The main purpose of this research is reuse of recycled aggregate in SCC and also to reduce use of fine aggregate by replacing manufactured sand. The SCC mixtures were prepared with 0, 25, 50, 75 and 100% replacement of recycle coarse aggregate in natural coarse aggregate and M-Sand in fine aggregate with a Water/Binder ratio of 0.36. Different test covering fresh properties of these SCC mixtures were executed the results were compared with EFNARC guidelines and IS 10262:2019. The feasibility of utilizing recycled aggregate and M-Sand in self compacting concrete has been examined and found that it is suitable for concrete.

scholarly journals The effect of elevated temperature on the lightweight concrete containing waste PET aggregate

2018 ◽  
Vol 6 (3) ◽  
pp. 1-14
Author(s):  
Semiha Akçaözoğlu
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Lightweight Aggregate ◽  
Unit Weight ◽  
Residual Compressive Strength ◽  
Flexural Tensile Strength

In this study, the effect of waste PET as lightweight aggregate (WPLA) replacement with conventional aggregate on the some physical and mechanical properties and residual compressive strength of concrete was investigated. For this purpose, five different mixtures were prepared (the reference mixture and four WPLA mixtures including 30%, 40%, 50% and 60% waste PET aggregate by volume). The fresh and dry unit weights, compressive strengths, flexural-tensile strengths, water absorption and porosity ratios of the mixtures were measured. In addition the specimens exposed to elevated temperatures at 150, 300 and 450 °C and the residual compressive strengths were measured. Test results indicated that the unit weight, compressive strength and flexural-tensile strength of the specimens decreased as the amount of WPLA increased in concrete. After exposing to elevated temperature, WPLA mixtures retained their structural integrity and compressive strengths at 150 °C and 300 °C. However there was a significant decrease in the residual compressive strength values of WPLA mixtures at 450 °C.

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