DPWH MANUAL (TYPES OF CRACKS & WEARING OF CONCRETE PAVEMENTS)

Question 1

A series of interconnected or interlaces cracks used by fatigue failure of the asphalt concrete surface under repeated traffic loading.

Answer 1

Alligator Cracking

Question 2

Cracks forming large interconnected polygons, usually with sharp corners or angle. These cracks are generally caused by hardening and shrinkage of the asphalt and or reflection cracking from underlying layers such as cement-treated base.

Answer 2

Block Cracking

Question 3

Cracks approximately at right angles to the pavement centerline. These may be caused by shrinkage or differential thermal stress of the asphalt concrete or maybe reflective cracks.

Answer 3

Transverse Cracking

Question 4

Cracks approximately parallel to the pavement centerline. These are caused by poorly constructed construction joints and shrinkage of asphalt concrete surface.

Answer 4

Longitudinal Cracking

Question 5

Wearing way of the pavement surface caused by dislodging of aggregated particles and binder. This is usually a result of insufficient asphalt binder in the mix or stripping of asphalt from particles of aggregate.

Answer 5

Raveling

Question 6

Progressive disintegration of the surface between the wheel paths caused by dripping of gasoline or oil from vehicles.

Answer 6

Drip track raveling

Question 7

The exuding of bitumen onto the pavement surface, causing a reduction in skid resistance.

Answer 7

Bleeding or flushing

Question 8

Elevation differences between adjacent slabs at transverse joints. It is usually the result of pumping and is a major source of Portland concrete pavement failure.

Answer 8

Faulting

Question 9

Localized upward buckling and shattering of the slabs at transverse joints or cracks. They can occur when transverse joints are filled with incompressible solid materials.

Answer 9

Blowups

Question 10

The breakdown or disintegration of slab edges at joints or cracks, usually resulting in the loss of sound concrete and the progressive widening of joint or crack.

Answer 10

Joint spalling

Question 11

Abnormal surface wear, usually resulting from poor quality surface mortar or coarse aggregate.

Answer 11

Surface attrition

Question 12

Loss of the original texture due to the traffic action.

Answer 12

Surface polish

Question 13

The overall track structure typically consists of:

Answer 13

1. Subgrade
2. Ballast
3. Ties
4. Rails
5. Rail fastening
6. (Spike is not included)

Question 14

Used to fasten rails together longitudinally.

Answer 14

Joint Bars

Question 15

Steel bars used to maintain gage at critical location such as curves and switches.

Answer 15

Gage Bars

Question 16

Used to resist the longitudinal motion of rails relative to ties.

Answer 16

Rail anchors

Question 17

The distance between the rails is what known as?

Answer 17

Standard gage