Utilization of Brick Aggregate in Concrete

IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 05, 2016 | ISSN (online): 2321-0613

Utilization of Brick Aggregate in Concrete Ayush Bhardwaj Department of Civil Engineering Abstract— due to continuous spreading of urbanization and industrialization, a significant problem of accumulation and management of construction waste is arising. To eradicate this problem construction and demolition waste are being recycled and used as a raw material for construction of new structures. Recycled brick aggregates which are recovered from destroyed masonry structures can be consumed to manufacture newer concrete mixtures. To ensure a sustainable waste management technique a detailed study of its engineering properties and purpose of utilization has to be specified.

Key words: Cement Concrete, Clay Bricks, Crushed Aggregate

raw material. The grain size distribution of natural and crushed brick aggregates is shown in Figure 1.

I. INTRODUCTION In the recent years, the wastes from construction and demolition zones are of large volume and that this volume is increasing year by year which is of great concern.

Predominantly in India, a huge quantity of waste is produced every year from construction sites and due to failure of buildings from earthquakes [1,2]. Whereas, the demand for housing is estimated to be more than two millions units and conventional construction materials like natural sand and aggregate are becoming rare [3]. Waste disposal is a serious environmental issue, especially for tier one cities where there is lack of disposal sites. Wastes from construction sites, material factories, demolition sites, and earthquakes are until now rarely used in India. Therefore it is needful to recycle as many waste materials possible.

Crushed bricks as aggregates can be used to help in minimizing the problem of waste dumping and successively helps in safeguarding of the natural aggregate resources.

There are however some complications in the use of crushed bricks aggregates in concrete. Codal limitations on water absorption and presence of impurities and lack of knowledge about the behavior of concretes made of crushed bricks creates a mistrust in users. One of the first use of crushed brick as an aggregate material with Portland cement was recorded in Germany (1860) for the manufacturing of small scale concrete products, but the first noticeable use of crushed brick as coarse aggregates in recent years has been recorded for the rehabilitation of destructed structures after the Second World War [4].

The aim of this paper, is to present the results of bricks aggregates used as coarse aggregate. Replacing natural aggregate in the varying percentage of 0, 25, 50, 75 or 100 % be weight. Compressive and flexural strengths are evaluated and compared till 28 days of age. Specific properties of the aggregates are also compared. Porosity, water absorption, water permeability and shrinkage are also measured.

II. EXPERIMENTAL SETUP The experimental procedure includes natural coarse (NG) and fine (NS) calcareous aggregates, coarse (RG) and fine (RS) crushed bricks aggregates and a Portland cement as

Fig. 1: Grain size distribution of aggregates Recycled brick aggregates shows a relatively low bulk density and high water absorption compared to natural aggregates. The higher water absorption of crushed brick aggregates is due to the higher porosity of the clay bricks.

Properties NG NS RG RS Specific weight (kg/m3) 2822 2987 2232 2496 Bulk density (kg/m3) 1695 1847 1924 1010 Water absorption (%) 1.5 1.0 11.5 14.0 Porosity (%) – – 38.82 59.54 Table 1: Properties of aggregates Four mixes are produced by replacing various percentage of the natural coarse aggregate by recycled crushed brick aggregate. The mix design is in compliance to IS 10262:2009, with 1119 kg of coarse aggregates, 730 kg of fine aggregates and 350 kg/m3 of cement. To limit the number of mixes and to compare them on a common basis, water cement ratio is being varied to obtain a constant slump of 60–80 mm for all the mixes.

Mix Type of NG RG NS RS W/C notation concrete (%) (%) (%) (%) C0 C0 0.61 100 0 100 0 C1 C25 0.60 75 25 100 0 C2 C50 0.59 50 50 100 0 C3 C75 0.58 25 75 100 0 C4 C100 0.57 0 100 100 0 Table 2: Composition of concrete mixes Each test is performed on three specimens and the averages of the three values were taken.

The compressive strength was measured at the ages of 3,7and 28 days, respectively on cubic 150 mm × 150 mm × 150 mm specimens using a testing machine with a maximum load capacity of 3000 Kn. The flexural strength was measured on 150 mm × 150 mm × 750 mm specimens at the ages of 7 and 28 days by a four-point bending test, using a testing machine with a maximum load capacity of 30 kN. All the molds were initially covered by plastic sheets and stored for 24 h in the laboratory before demolding, they were cured at room temperature. The rate of capillary absorption of water is

All rights reserved by www.ijsrd.com

1331

Utilization of Brick Aggregate in Concrete (IJSRD/Vol. 4/Issue 05/2016/324)

evaluated on mature concrete 28 days old and using 75 mm × 75 mm × 75 mm block specimens.

III. RESULTS AND DISCUSSION A. Fresh Concrete Properties In order to compare all the specimen on a common basis, entire research is carried out at a constant workability (slump between 50 mm and 65 mm), the water content has been adjusted accordingly and is shown in Fig. 2. Erstwhile to mixing the crushed brick aggregate is soaked in water for 24 hours and brought to saturated surface dry condition (SSD), so that it does not absorb water from the mix.

surface roughness should be advantageous in making a good bond between the crushed brick aggregates and the cement matrix, which could therefore increase the flexural strength performances [5]. At 28 days of age, a decrease of about 15% reaching up to 40% when coarse recycled aggregates concrete are used.

The results obtained seem to be in contradiction with that found by Akhtaruzzaman who observed an increasing trend in flexural strength of concrete made of crushed brick aggregates [16].

The ratio between compressive/flexural strength varies from 8.1 to 11.8 and the formula proposed by Dreux [7] could very well predict the experimental results. As for the compressive strength, the use of a plasticizer admixture increases significantly the flexural strength of about 75%.

D. Water Absorption Test The water absorption test, allow us to track the evolution of the magnitude of largest capillary veins on the surface of the specimen [18]. A deduction can be made about the dimension of the large capillaries and the volume of the fine capillaries. Therefore making it possible to compare the concrete with recycled aggregate with the concrete havingx natural aggregate in terms of durability. [18, 19]. A positive effect by decreasing the water absorption rate is shown by the use of plasticizer.

Fig. 2: Water content in mix The color of the concrete recycled brick specimen changes from greyish to a pink tinted color according to the percentage of recycled aggregates. The densities were found to be lower in case of crushed brick concrete, whereas the entrained air percentage increased B. Compressive Strength The compressive strength of the various mixes are portrayed in Fig. 3 for ages of 3,7,28 days. It can be clearly observed that compressive strength shows a decreasing trend for crushed brick concrete with respect to the rate of substitution. At 28 days old, the decrease in compressive strength is about 15–30 % in case of recycled coarse aggregates concrete as compared to natural aggregate concrete.

IV. CONCLUSIONS The following conclusions can be made based on the present investigations: 1) Recycled brick aggregates present relatively lower bulk density up to 17%, and higher water absorption compared to natural aggregates.

2) The decrease in compressive strength at 28 days of age was about 35 to 40% when coarse aggregates are substituted.

3) Water reducing and plasticizer admixtures are highly recommended to reduce the water content in the mix.

The decrease of flexural strength was about 15% in substituted mix.

4) The modulus of elasticity varies in the same way as the compressive strength and a reduction of 30%, was observed for coarse crushed bricks concrete.

5) For an ideal application of this type of concrete, the level of replacement should be limited to 25%.

6) Due to the low performance of concrete with crushed bricks aggregates, application of concrete used in structural member should be limited and be used in pavements and foundation bases.

REFERENCES

Fig. 3: Compressive Strength C. Flexural Strength A decrease in flexural strength is observed in a similar pattern to that observed for compressive strength even though the angular shape of the brick material and its

[1] ebieb F. Valorisation des de´chets de briques et be´ton de de´molition comme agre´gats de be´ton, Master Thesis, University of Blida, Algeria; 1999.

[2] Kenai S, Debieb F, Azzouz L. Mechanical properties and durability of concrete made with coarse and fine recycled aggregates. In: International congress for challenges of concrete construction. University of Dundee, UK; 2002. p. 383–92.

[3] Kenai S, Benna Y, Menadi B. The effect of fines in crushed calcareous sand on properties of mortar and concrete. In: Proceedings of the international

All rights reserved by www.ijsrd.com

1332

Utilization of Brick Aggregate in Concrete (IJSRD/Vol. 4/Issue 05/2016/324)

conference on infrastructure regeneration and rehabilitation: a vision for the next millennium, Sheffield; 1999. p. 253–61. [4] Hansen TC. Recycling of demolished concrete and masonry, RILEM Report No. 6, London E and FN Spoon; 1992.

[4] Devenny A, Khalaf FM. The use of crashed brick as coarse aggregate in concrete. Masonry Int 1999; 12:81– 4.

[5] Hendriks CF. European standard for recycled aggregates in construction. Congress Proceeding R99, vol. 3, Switzerland: Geneva; 1999. p. 108–13.

[6] Dreux G, Fiesta J. Nouveau guide du be´ton. 7th ed.

Paris: Eyrolles; 1995.

[7] French standard NF P18-406, Essai de compression, AFNOR, Paris; 1981 [in French].

[8] French standard NF P18-407, Essai de flexion, AFNOR, Paris; 1981 [in French].

[9] International standard ISO 6784, De´termination du module d’e´lasticite´ statique en compression; 1982 [in French].

[10] French standard NF P18-432, Essai de retrait, AFNOR, Paris; 1981 [in French].

[11] French standard NF P10-502, Be´ton-Capilarite´, AFNOR, Paris; 1989 [in French].

[12] Belgian standard NBN B15-222, Essai de flexion, AFNOR, Paris; 1981 [in French].

[13] Desmyter J, Van Dessel J, Blockmans S. The use of recycled concrete and masonry aggregates in concrete: Improving the quality and purity of aggregates. In: Proceedings of the international conference. dundee; 1999. p. 139–49.

[14] Kibriya T, Speare PRS. The use of crushed brick coarse aggregate in concrete. In: Proceedings of the international conference, Dundee; 1996. p. 495–503.

[15] Akhtaruzzamana A, Hasnat A. Properties of concrete using crushed brick as aggregate. Concr. Int. 1983(2):58–63.

[16] Mougin JP. Cours de be´ton arme´ B.A.E.L 91. Paris: Eyrolles; 1992.

[17] Balayssac JP. Relation entre performances me´caniques, microstructures et durabilite´ des be´tons, Ph. D. Thesis, National Institute of Sciences Applied, University of Toulouse; 1992.

[18] Wirquin E, Hadjieva-Zaharieva R, Buyle-Bodin F. Utilisation de l’absorption d’eau des be´tons comme crite`res de leur durabilite´application aux be´tons de granulats recycle´s (in french). Mater Struct 2000; 33:403–8.

[19] Levy S M, Helene P. Durability of recycled aggregates concrete: a safe way to sustainable development. Cem Conc Res 2004; 34(18): 1975–1980.

All rights reserved by www.ijsrd.com

1333