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Procedia APCBEE
ELSEVIER
APCBEE Procedia 5 (2013) 497 - 501
www.elsevier.com/locate/procedia
ICESD 2013: January 19-20, Dubai, UAE
Performance of Lightweight Foamed Concrete with Waste Clay
Brick as Coarse Aggregate
Norlia Mohamad Ibrahim , Shamshinar Salehuddin, Roshazita Che Amat, Nur Liza
Rahim and Tengku Nuraiti Tengku Izhar,
Performances of lightweight foamed concretes that are made from partial substitution of waste clay brick as coarse aggregate has been investigated in this study. The research aims were to identify the properties and characteristic of lightweight foamed concrete using waste clay brick as alternative materials to reduce the depletion of normal coarse aggregate from granite. Four different percentages of concrete mixtures using new coarse aggregate have been prepared that consist of 25%, 50%, 75%, and 100% waste clay brick. Foamed were injected into concrete mixture to produce lightweight concrete with appropriate proportions. The samples have undergone several testing including compression test, water absorption test, workability test and density test. From the results obtained, lightweight concrete that were produced with 25% substitution of waste clay brick showed the highest compressive strength of 25 MPa with density of 1647 kg/m3.
© 2013 The Authors. Published by Elsevier B.V.
Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society Keywords: Lighweight foamed concrete, waste clay brick, compressive strength, foam, aggregate
1. Introduction
Lightweight concrete composite were used successfully for many years for structural members and elements in buildings and bridges. Lightweight concrete can be defined as a type of concrete which includes an expanding agent in that it increases the volume of the mixture while giving additional qualities such as
* Corresponding author.
E-mail address: norlia@unimap.edu.my
School of Environmental Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
Abstract
2212-6708 © 2013 The Authors. Published by Elsevier B.V.
Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society doi: 10.1016/j.apcbee.2013.05.084
nailbility and lessened the dead weight [1]. The production of stable foam concrete mix depends on many factors such as selection of foaming agent, method of foam preparation and addition for uniform air voids distribution, materials section and mixture design strategies, production of foam concrete and performance with respect to fresh and hardened state are of greater significance.In addition to its lighter weight, which permits saving in dead load and so reduces the cost of both super structure and foundations, this concrete is more resistant to fire and provides better heat and sound insulation than concrete of normal density [2,3,4] .
2. Materials and Method
2.1. Preparation of samples
Raw materials that have been used in this research were Ordinary Portland Cement, granite as coarse aggregate, waste clay brick and fine aggregate. Other important materials were organic foaming agent and suitable water content. In this study, a total of 50 concrete cubes with dimension 100 mm x 100 mm x 100 mm have been produced. All samples were made using standard steel molds and were cleaned to avoid any impurities attached to concrete mixtures. One set of concrete specimens were also been produced as controls. After normal mixing of between granite, waste clay brick, cement, sand and water, foamed were injected into the concrete mixer during mixing process. The volumes of foamed needed in this study was determined based from targeted density at day 28. Foames are made from a mixture of water and natural organic chemical compound. Functions of these bubbles are to help entrapped air into the mixture and fulfilled the space. The samples have been tested for 7, 14 and 28 days respectively.
2.2. Determination of water absorption
Concrete specimens used in this research were prepared based from guidelines stipulated from British Standards (BS). Meanwhile testing cubes from fresh concrete was based from BS 8110:Part 108 [2]. Each batch of granite:waste clay brick ratio will undergone water adsorption testing. This test was needed to determine the capability of concrete cubes to adsorp water. The method of determination water absorption capacity is determined by finding the weight of surface-dry sample after it has been soaked for 24 hr and again finding the weight after the sample has been dried in an oven the difference in weight, expressed as a percentage of the dry sample weight, is the absorption capacity. Absorption capacity can also be determined using BS absorption test. Result for each sample for every batch will be compared with controlled sample.
2.3. Determination of compressive strength
Compressive strength is the primary physical property of concrete. It is also a fundamental property used for quality control purposes for lightweight foamed concrete. Compressive strength can be defined as the ability of concrete specimen to sustain the axial load. There are three types of specimen that can be used to determine the compressive strength such as cylinder, cube or prism test. In this study, all lightweight concrete samples will be tested to determine its compressive strength at 7, 14 and 28 days.
2.4. Determination of density
The density of both fresh and hardened concrete is important as it can gives an idea related to concrete durability, strength and resistance to permeability. Hardened concrete density is determined either by simple dimensional checks, followed by weighing and calculation or by weight in air/water buoyancy methods (ELE
International, 1993). In this research simple method to determine the density of lightweight concrete sample was using the formula given below:
Density = Average Weight Of Samples (kg) (1)
Volume of Sample (m3)
3. Results and Discussion
3.1. Water absorption
From the test that has been conducted the highest water adsorption was for sample that contained 100% of waste clay brick with 19.26%. Meanwhile, the lowest water adsorption was for 25% waste clay brick usage regardless the water adsorption acquired by controlled sample. This is because the higher percentage of waste clay brick applied in each mixture, the total voids distributed in the samples will be increased. This will result in higher of water absorption capacity since samples are capable to absorb more water when more voids are distributed in it. It can be seen from Table 1.1 that water absorption capacity was increased when the percentage of waste clay brick usage was increased. 100% of waste clay brick shows the highest water absorption followed by 75%, 50% and lastly 25% of waste clay brick.
Table 1. Water absorption of concrete
% Waste Clay Brick Before After 24 hour Water Absorption capacity
(kg/m3 ) (kg/m3) (%)
Control 1684 1452 15.98
25 1666 1436 16.02
50 1760 1513 16.33
75 1884 1605 17.38
100 1870 1568 19.26
3.2. Compressive strength test
Performance of concrete with 25% of waste clay brick replacement is better compared to the rest of the other samples. From the compression test that has been conducted, the samples which consist of 25% clay brick have the highest compressive strength on day 28 with 25.68 MPa compared to other sample. Sample with the second highest compressive strength of 23.0 MPa on day 28 is WCB50, which using 50% of CSA. Shape and the texture of waste clay brick surface will influence the strength of concrete where the concrete with rough and unequal surface will produce the high adhesion between the particle and cement matrix. The overall result is shown in Table 1.2.
3.3. Density
Determination of density for each cube sample also was made. Table 1.3 represents the overall density for sample WCB25, WCB50, WCB75 and WCB100. All of these samples were compared to controlled samples. From this table, it can be noted that sample WCB25 has density 1647 kg/m3 meanwhile for WCB50 it is slightly heavier with 1654 kg/m3. These lightweight foamed concrete made from waste clay brick has many
advantages as it can reduce the dead load of structure and overall costing [5]. The density for 100% waste clay brick is higher than control lightweight concrete because it absorbs more water during curing process
Table 2 Compressive strength of concrete after 28 days.
Item % of waste clay brick Average Strength (Mpa)
Control 0 25.912
WCB25 25 23.00
WCB50 50 18.83
WCB75 75 17.31
WCB100 100 6.25
Table 3. The density of lightweight concrete after curing 28days
Sample Average density (kg/m3)
Control 1631
WCB25 1647
WCB50 1654
WCB75 1720
WCB100 1734
4. Conclusion
The most optimum percentage of waste clay brick to be added into lightweight concrete mix is 25%. This is because 25% of waste clay brick in lightweight concrete provide better properties of lightweight concrete (compressive strength and durability). Workability of lightweight concrete increase when waste clay brick is applied in lightweight concrete mix. But decrease of the percentage of waste clay brick lightweight concrete will be making higher of compressive strength. Waste clay brick able to provide high permeability and absorption on the durability performance of lightweight concrete.
References
[1] Carrasqillo RL, Nilson AH. Micro cracking and engineering properties of high strength concrete research report, No. 80-1, Department of Structural Engineering, Cornell University, Ithaca;1980.p.254-60.
[2] Haman JA. Replacement of lightweight aggregate fines with natural sand in structural concrete. ACIJ 1964; 61:779-94.
[3] Kluage RH, Sparks MM. Lightweight aggregate concrete.ACI J 1949;45:625-49.
[4] British Standard 1881: Part 122: 1983, Method of Determine of Water Absorption.
[5] Debieb F, Kenai S. The use of coarse and fine crushed bricks as aggregate in concrete. Construction Building Material 2008;22:886-93.
