# MODULUS OF RUPTURE & BREAKING STRENGTH OF CERAMIC TILES [IS-13630-PART-6]

## Objective

Determination of the modulus of the cracking and breaking strength of the entire tile by means of three point loading, with the central point in contact with the glazed surface of the tile.

## Device

• dry oven 110±5. capable of0C
• recording gauge – Accurate up to 2%
• two support cylindrical rods These rods are made of metal and the part of the rod which will be in contact with the test specimen must be covered with rubber of the required hardness. One of the thesis is the two rods should be slightly rotatable and the other should be slightly rotatable about their axis. The dimensions of the rod and the thickness of the rubber covering the metal rod should be as per Table-1.
• central cylindrical rod – The structure of this rod is similar to that of the support rod and it can be rotated slightly.

The dimensions of the rod and the thickness of the rubber covering the metal rod should be as per Table-1.

 Table 1 Rod diameter, rubber thickness and length Tile Dimension(mm) Rod diameter (D), mm. In Rubber Thickness (Tea), mm. In Overlap of tile supports beyond edge (I), mm. In 95 20 5 10 < 95 48 10 2.5 5 <48 18 5 1 2

## sample preparation process

1. Each sample consists of 7 or 10 numbers of test samples depending on their dimension. (See Table-2)
 Table 2 Tile Dimension(mm) Minimum number of test samples 48 7 <48 18 10
1. Better the entire tile should be tested to find the accurate test result. But if a tile is more than 300 mm in length or is non-rectangular in shape, cut it so that it fits into the testing machine.
2. Cut the specimens to 110±5. Dry in an oven at a temperature of0c until it attains a constant mass.

## Testing Process

1. Place a test specimen on the two support rods with the flashing surface facing up. It should be placed in such a way that the specimen projects beyond each support rod by a length of ‘l’ (as given in tbla-1).

pay attention: For extruded tiles, place the tiles so that the projecting ribs are at right angles to the support rods. For all other rectangular tiles, the longer side is at right angles to the support rod.

1. Place the central rod on the glowing surface of the test specimen and make sure it is at the same distance between the two support rods.

pay attention: If the tile has relief surfaces, then 2. findRa A layer of rubber of suitable thickness (as given in Table-1) on the central rod.

1. Apply load evenly such that 1±2 N/mm. To get the growth rate of stress of2/s.
2. Record the load (F) when the sample is broken.
3. Continue steps 1 through 4 for all test samples in one sample.

## Calculation of Exam Result

Average breaking strength and average modulus of rupture are calculated from an average of five acceptable test results.

A test is said to be acceptable if the specimen breaks within the central part of a length equal to the diameter of the central rod.

If there are less than five acceptable results, a second sample is tested containing twice the number of tiles and then a minimum of ten acceptable results are required to calculate the average value.

The breaking strength is calculated using the following formula.

s = fl / b

Where,

S = breaking strength, N . In

F = Weight required to break the tile, N. In

L = center-to-center length between two support rods, mm. In

b = tile width, mm. In

The rupture modulus is calculated using the following formula.

= 3fl / 2bh2

Where,

= modulus of rupture, N/mm . In2

F = Weight required to break the tile, N. In

L = center-to-center length between two support rods, mm. In

b = tile width, mm. In

H = Minimum thickness of the test specimen, measured along the broken edge after the test, mm. In

## report

The test report should include the following

• tile details
• number of test samples
• d, t, l, L & F . values ​​of
• The modulus of breakage and breaking strength of each test specimen.
• Average modulus of breaking and breaking strength.

## Reference

IS: 13630 (Part-6) – Ceramic Tiles – Test Methods, Basis for Sampling and Acceptance [Part 6 – determination of modulus of rupture and breaking strength]

Er. Mukesh Kumar

Er. Mukesh Kumar is Editor in Chief and Co-Funder at ProCivilEngineer.com Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.