Nonconcrete Building Case-1

1)    Building description

The building under study is located in ----------. The building consists of a ground floor and one level above only. The building is used as accommodation for workers. There is no setback for the building where all the buildings are attached to each other.

The structural system of the building is a bearing wall system that consists of blockwork walls supporting wood beams that carry plywood and corrugated sheets. These blockwork walls are supported by rock strip footings that transfer the loads to the founding strata. The blockwork walls are filled with cement mortar.

2)    Visual inspection

During the physical observation, considerable areas were exposed and checked, and a general assessment was conducted. Investigation for various signs of deterioration was inspected, such as cracks' patterns, delamination of concrete, etc. Also, signs of excessive deflection and distress such as differential settlement and shear cracks were carried out.

 

The physical observations made during the inspection are summarized below, and figures from 2 to 11 present part of the conducted visual observation.

 

1.     Vertical and horizontal cracks were observed in the building’s walls.

2.     Most of the wood beams are worn. Also, some of the beams are highly stressed and deflected.

3.     Many beams are rotten with clear trails of mold.

4.     Roof plywood is deteriorated in many places and removed in some areas.

5.     Several places have a sign of water leakage.

6.     Corrugated sheets are eroded in several spots.

7.     Humidity is obvious in all rooms.

8.     Walls paint peeling is clear in many places, as well as the separation of the finishing layer.

9.     Many walls patching and repaired defects were observed.

10.  An unleveled floor is noticed in many places.

11.  Many services serious problems were observed.

 

3)    Tests

 

Due to the nature of the building and the uncertainty about the existence of reinforced concrete elements, tapping the walls with a steel hammer was carried out to locate concrete areas to inspect, but no concrete elements were found.

However, a verification core was extracted from one area, and it was evident that the wall was built from blockwork filled with cement mortar.

 

A trial pit had been dug to inspect the type of footings. The trial pit was located at the corner of some buildings and the excavation reached to the external wall foundation.

     

4)    Discussion of the Visual Inspection

Based on the conducted visual inspection and observations, and the experience with similar buildings, the structure had been undergoing a normal deterioration due to the aging effect combined with the influence of the temperature and humidity variation, and lack of proper and continuous maintenance. Also, due to the footing nature, some places experienced settlement due to the strata subsidence that led to diagonal cracks.

The excessive deflection in some of the roof’s beams leads to ponding that allows the rainwater to accumulate and deteriorate the roofing system further.

Improper compaction and the Chloride content in the flooring screeds had led to the subsidence in flooring cracks in some areas.

5)    Conclusion

From the preceding observation and investigation, the structural condition of the building is considered bad, and 80% of the building’s structure requires extensive maintenance, retrofitting, and robust.