Fracture Mechani

cs of Rubber

Concrete- Chinmay Khandelwal(Graduate Student)

IndexO PurposeO Causes of FractureO Process parametersO Test MethodsO ResultsO GraphsO ConclusionO References

Why Use Rubber in Concrete?

O Significant changes in toughness, ductility, plastic deformation, and impact resistance of concrete.

O Scrap tires can be recycled.

O Rubber has excellent adhesion to metallic cords which helps maintain its integrity for a long time.

How does fracture occur? O The Role of Chloride ions

O Freeze-Thaw deterioration

O Chemical attack

O Alkali Aggregate Reactivity

O Abrasion/Erosion

Process Parameters

Test Methods Wedge Splitting test Notch Tensile test

ResultsPros Cons

1. Reduction in static and dynamic modulus of elasticity indicates higher flexibility.

1. Compressive strength decreases with increase of replacement levels.

2. Water permeability increases with increase in the rubber content.

2. Microstructure analysis shows gaps between rubber fibers and cement paste which shows reduced strength.

3. Increase in the fracture energy. 3. Lower Bond strength

4. Higher plastic deformation capability

5. Increase in ductility.

Graphs

Con-trol

25% 50% 75% 100%00.10.20.30.40.50.60.7

Replacement Ratio v/s KIC

KIC

KIC

(Mpa

/√m

)

Replacement Ratio

Control 25% 50% 75% 100%0

50

100

150

200

250

300Replacement Ratio v/s GIC

GC

Replacement Ratio

GC

(Nm

/m^

2)

Control 25% 50% 75% 100%0

50

100

150

200

250

300

350Replacement Ratio v/s Gf

Gf

Gf (N

m/m

^2)

Replacement Ratio

ConclusionO Adverse effect on the compressive strength, splitting tensile

strength, and static elastic modulus.O The fracture energy increases up to certain replacement

level. Optimum dosage of 10%.O The failure modes show that the incorporation of rubber

granules either delays the failure of the concrete specimens or reduces the degree of failure.

O Higher rubber contents correlated to lower degrees of failure.

O The specimens retain greater integrity as the rubber particle size is increased, indicating that the strength of the concrete is increased with the particle size.

ReferencesO Atahan, A. O.; Sevim, U. K. 2008. Testing and comparison of concrete

barriers containing shredded waste tire chips, Materials Letters 62(2122): 37543757.

O Siddique, R.; Naik, T.R. Properties of concrete containing scrap-tire rubber—An overview. Waste. Manage. 2004, 24 (6), 563–569.

O Aamr-Daya, E., Langlet, T., Benazzouk, A., Queneudec, M., 2008. Feasibility study of lightweight cement composite containing flax by-product particles: physicomechanical properties. Cem. Concr. Compos. 30, 957e963.

O Influence of waste rubber utilization on the fracture and steel–concrete bond strength properties of concrete Mehmet Gesoglu, Erhan Güneyisi, Osman Hansu, Süleyman _Ipek , Diler Sabah Asaad⇑

O Kumaran, G. S., Mushule, N. and Lakshmipathy, M., 2008. A Review on Construction Technologies that Enables Environmental Protection: Rubberized Concrete. Am. J. of Eng. and Appl. Sc. 1, 40-44.

O http://www.cement.org/docs/default-source/fc_concrete_technology/durability/is536-types-and-causes-of-concrete-deterioration.pdf?sfvrsn=4

Thank You!