Characteristics of self- compacting concretes with tire rubber wastes Prepared by: NAHLA N. HILAL Supervisor:Assoc.Prof.Dr.Erhan GÜNEYISI Hi everbody, at first I would like to my thanks to my advisor, examination committe. My subject…. January 2016

better quality and stability, Introduction Self-compacting concrete (SCC) can be placed and consolidating under its own-weight without any mechanical vibration. Advantages of (SCC) Greater strength, rapid construction, better quality and stability, reduced problems related with vibration and low noise-level in the construction sites and plants. Rubberized concrete When a portion of the fine or coarse aggregate is replaced with rubber scraps, we are gain the rubberized concrete, comparison with traditional concrete, the rubberized concrete is found to be cheap and resists more temperature.

industrial floorings Fuel for cement kilns Rubber tyre recycled carbon black feedstock Fuel for cement kilns

Recycled tire rubber as partial aggregate in concrete Rubber scraps in parks In marine environments as reefs Recycled tire rubber as partial aggregate in concrete

AIM OF THE THESIS The main objective of the thesis is to investigate ‘The properties of the self compacting concretes made with fly ash and tire waste’. For this purpose, an experimental program was conducted in two stages The first part covered the sieving of scrap tire rubber to three sizes (FCR, CCR,MCR and Tire chip) and found specific gravity for each type. The second part of the thesis included the production of the self-compacting rubberized concretes (SCRC), and testing of fresh and hardened properties.

MATERIALS CEM I 42.5 R ordinary Portland cement. Class F type fly ash Superplasticizer(Glenium 51). A mixture of natural sand and crushed sand was incoporated in the concrete production as well as natural coarse aggregate. Two types of scrap tire rubber, crumb rubber (CR) and tire chips (TC) came from used truck tires castaway after a second recapping were utilized. Steel bar with 16 mm and length 500 mm.

The photographic views of No.18 and No.5 crumb rubbers and tire chips

Mix proportions for self-compacting rubberized concrete (kg/m3) Mixes Cement Fly Ash Water SP NS CS NG FCR CCR TC Control 364 156 182 3.38 573.57 245.81 819.38 0.00 FCR5 3.64 544.89 233.52 819.06 7.94 FCR10 3.90 516.21 221.23 818.74 15.88 FCR15 4.16 487.53 208.94 818.42 23.82 FCR20 4.42 458.85 196.65 818.10 31.76 FCR25 4.68 430.17 184.36 817.77 39.70 CCR5 10.64 CCR10 21.28 CCR15 31.92 CCR20 42.56 CCR25 53.20 MCR5 3.75 5.62 MCR10 7.49 11.24 MCR15 16.86 MCR20 14.99 22.48 MCR25 18.73 28.10 TC5 778.41 15.42 TC10 737.44 30.84 TC15 696.47 46.26 TC20 655.50 61.68 TC25 614.53 77.10

Concrete Mixing According to this mixing procedure by Khayat et al. (2000) The crumb rubber, fine and coarse aggregates in a power-driven revolving pan mixer were mixed homogeneously for 30 seconds, half of the mixing water was added into the mixer and it was allowed to continue the mixing for one more minute. After that, the crumb rubber and aggregates were left to absorb the water in the mixer for 1 min. Thereafter, the cement and fly ash was added to the mixture for mixing another minute. Finally, the SP with remaining water was poured into mixer, and the concrete was mixed for 3 min and then left for a 2 min rest. At the end, to complete the production, the concrete was mixed for additional 2 min.

TESTS ON SCRC slump flow A-Fresh Properties To measure the slump flow, an ordinary slump flow cone is filled with SCC without any compaction and leveled. The cone is lifted and average diameter of the resulting concrete spread is measured as seen. slump flow

V-funnel flow time test To measure the V-funnel flow time filling the V-shaped funnel with fresh concrete, thereafter, the hinged trapdoor is released and the flow time measured until it completely becomes empty. V-funnel flow time test

To measure L-box height ratio and T20and T40 flow time the test procedure is pouring fresh concrete in the vertical section and then the gate is opened and let the concrete flows to horizontal section through the gaps between the obstructing bars. L-box test

Views of rheometer and detailed schematic representation ICAR rheometer was used to characterize the rheology of SCRCs fresh self-compacting concrete was poured up to a height of 300 mm in to 300 mm diameter container in which a 125 mm diameter and 125 mm height four-bladed vane was placed in the centre of the container with a 87.5 mm spacing above and below the vane. Flow curves for every fresh concrete mixture was obtained representing shear stress and shear rate. Views of rheometer and detailed schematic representation

The number of casting samples for each mix

B- Mechanical Properties SCRCs Compressive strength Splitting tensile strength

Modulus of Elasticity

Fracture energy In order to obtain the fracture energy (GF) of SCRCs, the test was carried out coinciding with of RILEM 50-FMC (1985). The measurement of displacement was observed simultaneously via a linear variable displacement transducer (LVDT) at midpoint of span. A testing machine (Instron 5590R) The beams having length of 500 mm and cross-section of 100x100 mm were cast for the fracture energy test. The opening notch was achieved through reducing the effective cross section to 60x100 mm via a saw .

Characteristic Length Net Flexural Strength The notched beams were used to calculate the net flexural strength using the following equation on the assumption that there is no notch sensitivity. Characteristic Length By the following expression, the brittleness of materials can be determined in terms of characteristic length .

Bond Strength: The stress acting parallel to the bar along the interface is called bond stress

Detail of the bond strength test specimen An adequate concrete cover is necessary in order to properly transfer bond stresses between steel and concrete

Slump Flow Diameter of SCRCs The longitudinal particles blocked the rolling of other ingredients in the mixtures, which adversely affect the self-compatibility of concrete.

Slump Flow Time of SCRCs

V-funnel Flow Time of SCRCs an increase in the TC content is accompanied with segregation.

L-box Height Ratio of SCRCs

2.84s

29.68 s 7.04 s

Torque versus rotational speed obtained from rheometer for SCRC produced with: a) No.18 utilization of rubbers, which are not spherical as much as natural aggregate, increased the applied torque. Aggregate shape and texture are strongly effective on the rheology of self-compacting concretes.

b) No.5 CR

c) Mixed crumb rubbers

d) Tire chips

Use of 25% of No.18 resulted in 6.2% increase ‘n’ Application of the Herschel-Bulkley model on the rheological data for the SCRC produced with: a) No.18 Use of 25% of No.18 resulted in 6.2% increase ‘n’

25 %NO.5CR increased the exponent ‘n’ values as much as 24.2% b) No.5 25 %NO.5CR increased the exponent ‘n’ values as much as 24.2%

c) Mixed crumb rubbers 25 %MCR increased the exponent ‘n’ values as much as 20.2%.

25% of TC resulted in 36.0% increment ‘n’ value . d) Tire chips 25% of TC resulted in 36.0% increment ‘n’ value .

Application of the modified Bingham model on the rheological data for the SCC produced with: a) No.18 c/µ=0.253 ‘c/µ=0.362 ’

b) No.5 ‘c/µ=’ 1.054

c) Mixed crumb rubbers moderate ‘c/µ= 0.814’

d) Tire chips highest ‘c/µ ’ The replacing the spherical grains, natural aggregate, with longitudinal grains, rubber, needed the higher torque values at the same rotational speed.

There is a strong relationship between ‘c/µ’ coefficients and exponent ‘n’ values.

Higher reduction with FCR Lower reduction with TC Fresh Density of SCRCs Higher reduction with FCR Lower reduction with TC

Compressive Strength of SCRCs at 28 days 62.8 Control 58.3 FCR5 31.0 TC25

Compressive Strength of SCRCs at 90days 72.4 Control 68.0 FCR5 35.5 TC25 Rubber is a soft material and the adhesion between rubber particles and cement paste is low.

Splitting Tensile Strength of SCRCs 90 days 4.36 Control 2.24 CCR25

Net Flexural Strength of SCRCs at 90 days This behavior may be related to the very low adhesion between the chipped rubber and the cement paste.

Fracture Energy of SCRCs at 90 days FCR5 143.5 TC5 141.2

Typical loads versus displacement curves ofNo Typical loads versus displacement curves ofNo.18CRwith respect to control mix

Typical loads versus displacement curves ofNo Typical loads versus displacement curves ofNo.5CRwith respect to control mix

Typical loads versus displacement curves of MCR with respect to control mix

Typical loads versus displacement curves of tire chip with respect to control mix

Characteristic Length of SCRCs at 90 days

14.6 poor bonding characteristic around rubber tires and cement paste and . There are a lot of micro - cracks near the ITZ in the rubberized concrete.

CONCLUSIONS It is very clear from the test results that all most the mixes satisfy the requirements of SCC with respect to EFNARC (2005). Densities in the range of 2344 - 2192 kg/m3 were produced. The slump flow diameters ranging from 560 to 750 mm were obtained for the self-compacting rubberized concretes. Replacing the crumb rubber with fine aggregate increased both T50 slump flow and V-funnel flow times while replacing the tire chip with coarse aggregate decreased both T50 slump flow and V-funnel flow times.

using the crumb rubber caused increasing of the L-box T20 and T40 flow times. And replacement of coarse aggregates with the TC caused increasing of T20 and T40 flow times and decreasing of the L-box. The highest exponent ‘n’ values and ‘c/µ’coefficients were obtained when the natural coarse aggregate was substituted with tire chips, while the lowest values were achieved when the natural fine aggregate was replaced with FCR crumb rubber at each replacement level. The compressive strength of self-compacting rubberized concrete having more than 30 MPa could be produced easily. The self-compacting concretes produced with FCR gave the highest splitting tensile strength those produced with CCR gave the lowest splitting tensile strength.

The self-compacting concretes produced with (TC) gave the lowest static elastic modulus while the control mix gave the highest static elastic modulus. The control mix had greater net flexural strength compared to other mixture. The lowest reduction of fracture energy with 5FCR where it was 9%. The best value for ductility was obtained with MCR. It was observed decreasing of bond strength with increasing the crumb rubber and tire chip size and content.

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