--- title: "Bituminous maintenance and rigid pavement failures" subject: "Transportation Engineering II" chapter: 4 key: "semester_7/transportation_engineering_ii:bituminous-maintenance-rigid-failures" source: https://www.bctengineer.com/q/semester_7/transportation_engineering_ii/bituminous-maintenance-rigid-failures site: BCT Engineering --- # Bituminous maintenance and rigid pavement failures Transportation Engineering II · Chapter 4: Highway Maintenance, Repair, and Rehabilitation - Asked in: 2081 Baisakh, 8 marks; 2075 Chaitra, 8 marks (asked 2 times) - Video: [17 TE 2 Rigid pavement failure and maintenance](https://www.youtube.com/watch?v=koCr7xW7jFQ) — Civil Engineering Only - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/transportation_engineering_ii/bituminous-maintenance-rigid-failures - Whole chapter: https://www.bctengineer.com/md/semester_7/transportation_engineering_ii/chapter-4 ## Question Explain the maintenance of bituminous surface. Describe the typical types of rigid pavement failure. ## Short answer Bituminous surface maintenance includes patching potholes, sealing cracks, surface dressing for ravelling, spreading chips on bleeding, and periodic overlay. Typical rigid pavement failures are transverse cracking, corner breaks, faulting, pumping, spalling, blow-ups, and scaling. ## Answer #### Maintenance of bituminous surface **Highway maintenance** is the work done to keep a road, its pavement, shoulders, drainage, structures and furniture in a safe and serviceable condition and to preserve the investment, without changing the original design standard. Maintenance of a bituminous surface (IRC:82 and Nepal DoR maintenance manuals) depends on the defect: | Defect | Maintenance treatment | |---|---| | Potholes | Mark a square or rectangular patch, cut vertical sides down to sound base, remove debris, apply tack coat, fill with hot or cold premix, and compact (roller or hand rammer) to finish 5-6 mm above the surface | | Cracks (hairline/fine) | Seal with bitumen emulsion or slurry seal; for wider cracks, clean and fill with bitumen and sand or crack sealant | | Fatigue (alligator) cracking | Remove and replace failed area including base; overlay | | Ravelling / loss of aggregates | Surface dressing or seal coat; fog seal for light cases | | Bleeding / fatting up | Spread hot coarse sand or 6.7 mm chips and roll; or remove excess binder | | Corrugation, shoving, rutting | Scarify, add or remove material and recompact; level with a bituminous levelling course and overlay | | Edge breaking | Repair shoulders, widen the pavement or re-gravel; improve drainage | | Depressions | Fill with premix levelling course | | Worn surface | Premix carpet, surface dressing, slurry seal or thin overlay (periodic maintenance) | Drainage (cleaning side drains and culverts) and shoulder maintenance are essential, because water is the main cause of failure. #### Typical failures of rigid pavement Typical types of failure of a cement concrete pavement: | Failure | Description | Cause | |---|---|---| | **Transverse cracking** | Cracks across the slab | Late sawing of joints, joint spacing too long, thin slab, restrained shrinkage | | **Longitudinal cracking** | Cracks along the lane | Differential settlement, warping, thin slab, poor subgrade support | | **Corner break (corner crack)** | Triangular piece at the corner within 1.5 m of joint | Load at unsupported corner, loss of support (pumping), poor load transfer | | **Diagonal cracking** | Crack at about 45 degrees | Heavy corner loads, settlement | | **Punch-out / shattered slab** | Slab breaks into many pieces | Heavy repeated loads, weak sub-base | | **Faulting** | Step between slabs at a joint | Pumping, poor load transfer (dowel failure) | | **Pumping** | Ejection of water and fines at joints | Water under slab, loose subgrade, heavy traffic | | **Spalling** | Breaking of joint edges | Incompressible material in joints, weak concrete, dowel misalignment | | **Blow-up (buckling)** | Slab lifts and shatters in hot weather | Blocked expansion joints, insufficient expansion gap | | **Scaling and crazing** | Flaking and map cracks on surface | Over-finishing, poor curing, freeze-thaw | | **Joint seal failure** | Sealant loss, weeds | Aged sealant, poor installation | ```text Faulting at a joint Corner break ______ +-------------+ ______| step | | joint | | | crack -> / +-----------/-+ ``` Remedies include full-depth repair, slab replacement, dowel retrofit, grinding of faults, crack and joint resealing, undersealing (grout) to fill voids, and improving drainage. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Highway maintenance aims to: A. Upgrade the design standard of the road B. Keep the road in safe, serviceable condition without changing the original design standard C. Replace the whole pavement D. Widen carriageways Answer: B. Maintenance preserves the investment and serviceability without altering the original design standard. (Key point: Highway maintenance) 2. In pothole repair, the patch is: A. cut with sloping sides and left unrolled B. marked square/rectangular, cut with vertical sides to sound base, tack coated, filled with premix and compacted 5-6 mm above the surface C. filled with loose soil D. sprayed with prime coat only Answer: B. Vertical sides to sound base, tack coat, premix and compaction slightly above surface level (5-6 mm) is the standard method. (Key point: Pothole repair) 3. Bleeding (fatting up) on a bituminous surface is treated by: A. Spreading hot coarse sand or 6.6 mm chips and rolling B. Spraying more bitumen C. Fog sealing D. Slurry sealing Answer: A. Excess binder is blotted by hot coarse sand or small chips rolled in, or removed. (Key point: Bleeding) 4. Faulting in a concrete pavement is: A. A step between slabs at a joint caused by pumping or poor load transfer B. Cracking across the slab from late sawing C. Lifting of slabs in hot weather D. Flaking of the surface Answer: A. Faulting is a vertical step at joints, due to pumping and dowel/load transfer failure. (Key point: Faulting) ## Related in Transportation Engineering II - [Maintenance, rehabilitation, reconstruction; rigid failures](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Amaintenance-rehab-reconstruction-rigid-failures) — Transportation Engineering II, chapter 4 - [Repair vs rehabilitation; rigid pavement failures](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Arepair-vs-rehabilitation-rigid-failure-types) — Transportation Engineering II, chapter 4 - [Typical failures of flexible pavement](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Aflexible-pavement-failures-causes) — Transportation Engineering II, chapter 4, asked 2× - [Maintenance importance; bituminous pavement maintenance](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Aimportance-maintenance-bituminous-pavement) — Transportation Engineering II, chapter 4 - [Highway maintenance and causes of pavement failure](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Amaintenance-flexible-failures) — Transportation Engineering II, chapter 4, asked 2× - [Failures of rigid pavement](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Arigid-pavement-failures) — Transportation Engineering II, chapter 4, asked 2× ## Related in other subjects - [Gear tooth failure and surface durability](https://www.bctengineer.com/question.md?key=semester_6%2Fmachine_design_i%3Agear-tooth-failure-surface-durability) — Machine Design I, chapter 9