A.01.38_-_Attachment_5_-_Structural_Audit_Report.pdf

STRUCTURAL ENGINEERING AUDIT OF KOMBEWA

MICRO LAB IN KISUMU

MAY 2016

STRUCTURAL AUDIT REPORT

STRUCTURAL INSPECTION REPORT i Issue 1.0 / May 2016

STRUCTURAL ENGINEERING AUDIT OF KOMBEWA MICRO LAB IN

KISUMU

TABLE OF CONTENTS

Chapter Description Page

ABBREVIATIONS ............................................................................................................................. ii

EXECUTIVE SUMMARY .................................................................................................................. iii

1 INTRODUCTION ............................................................................................................................. 1-1

1.0 General 1-1

1.1 Background 1-1

1.2 Scope of Work 1-2

1.3 Site Survey 1-2

2 SURVEY OBSERVATIONS ............................................................................................................ 2-1

2.0 The Pharmacy 2-1

2.1 The Micro Biology Laboratory 2-2

2.2 The Kitchen 2-3

3 DISCUSSION .................................................................................................................................. 3-1

3.0 General 3-1

4 RECOMMENDATIONS AND CONCLUSION ................................................................................. 4-1

4.0 The Pharmacy 4-1

4.1 The Micro Biology Laboratory 4-2

4.2 The Kitchen 4-3

4.3 The Way Forward 4-3

5 APPENDIX 1 ................................................................................................................................... 5-4

5.0 The Pharmacy Photos 5-5

5.1 Micro-Biology Laboratory Photos 5-13

5.2 The Kitchen Photos 5-17

6 APPENDIX 2 ................................................................................................................................. 6-20

6.0 Sketches of Remedial Measures 6-21

7 APPENDIX 3 ................................................................................................................................. 7-22

7.0 Information Supplied by the Client 7-23

STRUCTURAL INSPECTION REPORT ii Issue 1.0 / May 2016

ABBREVIATIONS

Kg Kilogram

Nos. Number m Meter

Ltd Limited mm Millimetre

NDT Non Destructive Testing

RHS Rectangular Hollow Section

UB Universal Beam

RSJ Rolled Steel Joist

RC Reinforced Concrete c/c Centre to Centre

STRUCTURAL INSPECTION REPORT iii Issue 1.0 / May 2016

EXECUTIVE SUMMARY

General

GIBB Africa was commissioned by KEMRI / Walter Reed Project (USAMRD-K) to carry out a structural audit of their building facility at Kombewa. This comprised the following:

Inspecting the cracks appearing in the Micro-Biology Lab (31.1m²), Pharmacy (31m²) and Kitchen (19.6m²);

Determining the cause of the cracks;

Assessing the integrity of the building based on the specific cracks mentioned above;

Recommending remedial measures.

Audit Approach

A visual site inspection was carried out to establish the physical condition of the structural elements at the areas of concern. The structural systems of the building were studied and measurements of relevant structural elements taken and recorded for structural evaluation.

Photographs of the structural elements were also taken for records.

The audit was conducted within the extent that the structural elements were visible and easily accessible.

Audit Findings

During the survey, defects were noted on some parts of the structure and not on the entire structural system of the building.

These included the following:

Pharmacy

Structural cracks on the first floor slab;

Non-structural cracks on the first floor slab finishes;

Structural cracks on the free spanning beam.

Micro-Biology Laboratory

Structural cracks on the first floor slab;

Non-structural plaster cracks on the wall.

The Kitchen

Non-structural cracks on wall plaster and slab finishes.

STRUCTURAL INSPECTION REPORT iv Issue 1.0 / May 2016

Conclusion

The structural defects noted are critical and may be attributed to the following reasons:

Poor design of the first floor slab/beam structure;

Non-compliance to the design provided during construction;

Poor workmanship during construction.

From the approved structural drawings we have noted the following deficiencies:

The slab panel at the Microbiology Lab has adequate bottom reinforcement, however top reinforcement for the shorter panel supports are not provided;

The slab panels at the Pharmacy have adequate bottom reinforcement, however top reinforcement is missing at the beam support where the two panels join; and

The new suspended beam in the Pharmacy was merged with an exiting beam to form a larger 450 x 200 beam cross section. There is no indication of any knowledge of the existing beam reinforcement. The new bottom reinforcement provided in the beam is not placed in the tension zone.

Remedial works should therefore be undertaken to uphold the structural integrity of these elements of the building.

The ‘As built’ structural reinforcement drawings used for the first floor slab/beams were however not available for our review and comments.

Recommendations

We recommend remedial measures to be taken as follows:

Pharmacy

Introduce a steel beam/girder to the underside of the first floor slab to carry the partition wall above;

Provide additional steel joists to support the slab and relieve the distribution of the load to the concrete beams;

Repair the structural cracks on the free spanning beam;

Repair the cracked floor finishes.

Micro-Biology Laboratory

Introduce a steel beam/girder to the underside of the first floor slab to carry the partition wall above;

Provide additional steel joists to support the slab and relieve the span stresses;

Repair the cracked plaster finishes.

The Kitchen

Repair the non-structural cracks on wall plaster and slab finishes.

STRUCTURAL INSPECTION REPORT 1-1 Issue 1.0 / May 2016

1 INTRODUCTION

1.0 General

GIBB Africa was commissioned by KEMRI / Walter Reed Project (USAMRD-K) on 19 April 2016 to carry out a structural audit of their building facility at Kombewa. Specifically, the audit was meant to carry out the following:

Inspect the cracks appearing in the Micro-Biology Lab (31.1m²), Pharmacy (31m²) and Kitchen (19.6m²);

Determine the cause of the cracks;

Assess the integrity of the building based on the specific cracks mentioned above;

Recommend remedial measures.

A site inspection of the building was carried out on 6 May 2016.The aim of the survey was to determine the structural integrity of the building in relation to the possible defects already noticed by the Client. A general review was also carried out on the external fabric of the building to identify any structural defects.

This report presents the findings of the assessment and contains recommendations for the remedial works required to re-instate the structural integrity of the building.

1.1 Background

GIBB Africa was informed by the Client that the Structural Engineer for the project was the Ministry of Public Works in Kisumu.

The Building was initially designed and constructed as a single storey structure in 2002. In 2013, an extension to the building was done which involved construction of an additional floor. The Structural Engineer for the extension was Eng. M.A. Orot, while the architects were Arch.Otiende J. Moth and Arch. H.O Karwa. The contractor for the extension works was identified as Dabasia builders Ltd.

The structural system for the building is mainly load bearing masonry walls with isolated columns supporting parts of the first floor slab, roof and staircases.

KEMRI / Walter Reed provided the following information to GIBB as reference for this structural audit:

(a) Scheme architectural layout drawings for the extension works. These were the drawings used as the reference drawings during the audit with the assistance of the Client, since they were not the As-Built drawings for the building;

(b) Approved structural drawings;

(c) Approved scheme design architectural drawings;

(d) Material Test Certificates;

However, the following information was not available during the audit:

(a) “ As Built” drawings for the original building;

STRUCTURAL INSPECTION REPORT 1-2 Issue 1.0 / May 2016

(b) “As Built” structural drawings for the extensions;

(c) Structural design calculations.

1.2 Scope of Work

The scope of the consultancy services as contained in the Terms of Reference includes the following:

Visit KEMRI / Walter Reed Project Facility in Kombewa and undertake a structural integrity/audit of the Kombewa main building, more specifically the Micro-Biology lab, Pharmacy and the Kitchen based on the cracks noted by the Client. This was to be done through visual examination, in view of establishing;

o Soundness of the Structural Systems;

o Type and quality of materials used;

o Condition / deficiencies;

o Cause of defects and ;

o Remedial work required.

The sub-structure elements of the buildings were not evaluated since the defects identified did not show any relationship with the foundation structure of the building.

Submit a structural audit report and make recommendations on remedial works required for the defects noted.

1.3 Site Survey

The Consultants main task was to assess the structural integrity of the building based on the cracks already noted and advise on mitigating measures for any adverse findings.

A site Inspection was thus carried out on 6 May 2016 to assess the condition of the existing building based on the above. The survey included the following steps:

(a) A visual inspection of the building elements in the affected areas to assess their physical condition;

(b) A study of the structural systems in the affected areas to verify their integrity;

(c) Measurements of the relevant structural elements for evaluation; and

(d) Taking of photographs of the structural elements for records.

STRUCTURAL INSPECTION REPORT 2-1 Issue 1.0 / May 2016

2 SURVEY OBSERVATIONS

2.0 The Pharmacy

The Pharmacy is located at the ground floor level of the building and measures approximately 7m by 5m.

The structural system in this part of the building is load bearing masonry walls with an RC beam at the first floor slab level.

There is also a free standing beam supporting the 1st floor slab that spans 4.8m across the room.

(See Plate 5.1.1)

As previously noted, extensions and renovations were done on the original building. This involved construction of an additional floor above.

In the as built construction, the rooms above the Pharmacy i.e. Records & Computer Rooms (See Plate 5.1.15) have one wall supported directly on the slab above the Pharmacy. There is no direct transfer of loads to the foundation system for this wall. This wall also carries the loads from the gutter and the roof.

The following observations were made during the site survey:

Ground floor slab

The existing ground floor slab is in good condition. There was no evidence of structural damage, cracks or heave due to the soil below.

Walls and cladding

The masonry walls in the Pharmacy are adequately protected by plaster internally and no evidence of any weathered sections externally. The walls are plumb, without any internal/external structural cracks, generally smooth and no plaster defects (see Plate 5.1.1).

There was no moisture ingress noted in the walling which is mainly indicated by presence of green patches that would suggest severe attack by mould.

First floor RC Beams

There are 450x200 beams at the first floor level tying together the Pharmacy walls. These beams are supported on the load bearing masonry walling and they show no signs of deterioration. However there is also a free spanning beam that spans 5m (see Plate 5.1.2).This was noted to have structural cracks near the mid span of the beam. The cracks were noted in 4 places (see Plate 5.1.6, 7, 8 & 9).The exposed crack on the beam measured about 1mm.

It was also noted from the approved structural drawings that the entire first floor beams were designed to merge with the previously existing roof ring beams.

During hacking of the plaster to expose the concrete beam, it was noted that the quality of the concrete was poor and easily crumbled.

STRUCTURAL INSPECTION REPORT 2-2 Issue 1.0 / May 2016

There was no information regarding the class of concrete used in the construction, nor the as-built reinforcement used in the RC beam.

The First Floor Slab

The slab above the Pharmacy has moderate spans. These are on either side of the 5m RC beam described above. They measure 2.5mx5m for the panel near the back wall & 4.5x5m for the panel near the entrance.

The panels appear to have both hair width and 1mm cracks in various places (see Plate 5.1.3, 4 & 5). Some of the cracks are hairline plaster cracks and do not seem to be of a structural nature as they have no specific direction. However, the ones near the mid span of the slab panel nearer to the entrance were of concern (see Plate 5.1.3, 4 & 5). These are located where there is a partition wall resting above the first floor slab (see Plate 5.1.15).

The plaster was exposed at the mid span and the crack was noted to extend to the concrete slab structure (see Plate 5.1.13 & 14). The exposed crack on the slab underside measured about 1mm.The quality of the finished concrete works also appeared poor and the plaster did not have good bonding with the concrete slab.

Cracks of approximately 1mm were also noted at the top side of the slab at the supported wall. These are likely due to the deflection of the slab causing the terrazzo finish to crack (see Plate 5.1.16).

2.1 The Micro Biology Laboratory

The Micro Biology Laboratory is located at the ground floor level of the building and measures approximately 7.4m by 4.5m.

The structural system in this part of the building consists only of load bearing masonry walls tied with RC beams at the first floor level.

The architectural layouts for the building extension placed a wall of the kitchen above to be supported directly on the first floor slab near the mid-span of the slab. It was not clear whether the 1st floor slab was designed to carry this wall line load.

Ground floor slab

The existing ground floor slab is in good condition. There was no evidence of structural damage, cracks or heave due to the soil below.

The masonry walls in the Micro-Biology Laboratory are adequately protected by plaster internally with no evidence of any weathered sections externally. Cracks of approximately 0.5mm were noted in two places on the walls (see Plate 5.2.4 & 7).These cracks appear to be plaster cracks since they do not appear on the external side of the walls.

There was no moisture ingress noted in the walling which is mainly indicated by presence of green patches that would suggest severe attack by mould.

STRUCTURAL INSPECTION REPORT 2-3 Issue 1.0 / May 2016

RC Beams

There are 450x200 RC beams at the first floor level tying together the Micro-Biology Laboratory walling. These beams are supported on the load bearing masonry walls and they show no signs of deterioration.

The slab above appears to have a large span of approximately 7.4m by 4.5m. Cracks are visible on the ceiling plaster and appear to run in both directions. (see Plate 5.2.4, 5 & 6) This is likely due to deflection in both span directions. There is also evidence of leakage of water from the Kitchen above as indicated by peeling of paint on the slab (see Plate 5.2.7).

The most notable crack runs along the width of the slab at the location where the Kitchen wall above lies directly on the slab (see Plate 5.3.1). The crack extends a little below the ceiling along the wall near the circuit breaker (see Plate 5.2.3 & 4).This vertical crack is a plaster crack due to slab deflection.

Plaster was removed at this crack location and the extent of the crack on the structural member was examined (see Plate 5.2.8). The exposed crack on the slab measured about 1mm.

The quality of the finished concrete works also appeared poor and the plaster did not have good bonding with the concrete slab.

Cracks of approximately 0.5mm were also noted at the finishes on the top side of the slab at the supported wall. These are non-structural and are due to the deflection of the slab causing the terrazzo finish to crack (see Plate 5.3.2). However these cracks on the terrazzo finish may in future allow water to seep through the slab due to it’s poor quality concrete. The seepage, as was also noticed in another part of the slab (see Plate 5.2.7) is not good for the slab reinforcement and may cause rusting of the reinforcement bars and spalling of concrete in the future.

2.2 The Kitchen

The Kitchen is located at the first floor level of the building, above the Micro-Biology Lab and measures approximately 4.5m by 4.7m.

The structural system in this part of the building consists only of load bearing masonry walls with an RC ring beam at the roof level.

One of the Kitchen walls rests directly on the floor slab and there is no structural beam on the underside to support it at the Micro-Biology Lab below (see Plate 5.3.1 & 2).

The ceiling above is a suspended ceiling and there is a pitched roof above.

STRUCTURAL INSPECTION REPORT 2-4 Issue 1.0 / May 2016

The masonry walls in the Kitchen are adequately protected by plaster internally with no evidence of any weathered sections externally. Plaster cracks of approximately 0.5mm width were noted in various places on the walls (see Plate 5.3.3 & 4).

The wall that is placed directly on the slab has some cracks of approximately 0.5mm width noted on the plaster and at the bottom connection with the slab (see Plate 5.3.2).

The cracks noted on walls adjacent to the wall above have plaster cracks of approximately 1mm width due to the deflection of the slab causing the above wall to move leading to the observed cracking (see Plate 5.3.3). These cracks do not appear on the external side of the walls (see Plate 5.3.5).

Roof Beams

There is a 450x200 RC ring beam at the roof level tying together the kitchen walling.

There is also a gutter beam supporting part of the external walling (see Plate 5.3.5). This is a beam on load bearing masonry walls and shows no signs of deterioration.

There is also a plaster crack noted on the inner beam (see Plate 5.3.6). It appears on only one side and does not seem to be a structural crack.

The underside condition of the Kitchen slab has been described in section 2.2 above.

Hair width cracking of approximately 0.5mm were also noted at the top side of the slab at the supported wall (see Plate 5.3.2)

This is due to slab deflection causing the terrazzo finish to crack. This crack at the top is on the terrazzo finish only and not on the concrete slab.

STRUCTURAL INSPECTION REPORT 3-1 Issue 1.0 / May 2016

3 DISCUSSION

3.0 General

This structural assessment is based on the information that was readily available. This included available documents from the Client and data collected from the site through observation.

In as much as failures were noted on some structural elements, it was not possible to establish the party responsible because of unavailable information. These include but not limited to:

Class of Concrete at 28 days used in the construction (only 7 day cube test results were availed);

As-built Size, Type, Number and spacing of reinforcement used in the slab and beams;

Stage construction photographs; and Design calculations of the failing members.

The failure may either be occurring from a deficient design, in which the Structural Engineer made errors during the design or they may be from poor workmanship by the contractor regarding the quality or quantity of the materials specified for the construction.

Interim measures to prevent total failure should be taken as final remedial measures are being prepared. This includes propping the slabs along the supported wall locations and the free spanning beam in the Pharmacy to relieve them of the apparent excessive stresses.

Apart from the structural defects noted in the preceding sections, the rest of the building did not appear to show signs of structural deficiency except some maintenance works which are required for areas with leaking slabs due to poor workmanship by the contractor. These areas include the floor of the Kitchen and the toilets at the first floor next to the kitchen, which experience leakages during cleaning.

STRUCTURAL INSPECTION REPORT 4-1 Issue 1.0 / May 2016

4 RECOMMENDATIONS AND CONCLUSION

4.0 The Pharmacy

Two structural defects were noted in this location of the building. This was a failing slab panel and the 5m span free spanning beam. Remedial action should be undertaken on the various elements as follows:

The slab seems to be overloaded by the walling it supports above. It seems that the slab may either have been under reinforced or was not designed to carry the current loading.

As it stands, the slab carries the walling above it together with part of the roof as a line load.

We recommend provision of a structural steel beam or girder to be placed at the underside of the slab at the supported wall location. This will span 4.8 m and will be bolted to the first floor ring beams at the slab level to relieve the slab of this line load.

Having reviewed the data from site and documents issued by KEMRI, we are able to determine the magnitude of this line load so that the new supporting steel beam and its connections can be designed.

In order to mitigate effects of redistribution of stresses caused by introduction of a new steel beam/girder support under the wall, a series of light steel floor joists can also be provided to reduce the spans of the existing slab. The details of these steel joists are as shown in Appendix 2

The cracks noted can then be exposed and repaired using approved resin crack repair compounds and re-plastering done.

The 450x200 RC Beam Spanning 5m

From the approved structural drawings, it was noted that the new beams of the first floor were merged with the previously existing ring beams at that location. There is no indication of the existing beam reinforcement from the drawings. The beam may thus have been under reinforced hence the presence of structural cracks. The loading mentioned on the slab above is ultimately transferred to this beam and it seems that the beam has no capacity to carry this load. Having proposed a new steel supporting beam/girder to relieve this load, the adverse loading on this 450x200 RC beam is significantly reduced. The existing cracks can be exposed and repaired using approved resin crack repair compounds.

Refer to Sketch No.2 in Appendix 2 for the proposed rehabilitation details of the Pharmacy.

STRUCTURAL INSPECTION REPORT 4-2 Issue 1.0 / May 2016

4.1 The Micro Biology Laboratory

The main structural defect noted in the Laboratory was the failing first floor slab.

The minor cracks of approximately 0.5mm appearing on the wall were not structural and were due to the effect of the slab deflection.

Remedial action should be undertaken as follows:

The slab panel measured 7.4m by 4.5m and had a line wall load on it which led to development of structural cracks. Again it seems that the slab may either have been under reinforced or was not designed to carry the current loading.

This wall load is located at approx 2.5 m from the end of the shorter span of the slab.

It is at this location that structural enhancement should be done.

We recommend provision of a structural steel beam/girder to be placed at the underside of the slab at the wall location. This will span 4.3 m and will be bolted to the ends of first floor beams at the slab level to relieve the slab of this line load.

In order to mitigate effects of redistribution of stresses caused by introduction of this new steel beam/girder support under the wall, a series of light steel floor joists can also be provided to reduce the spans of the existing slab.The details of these steel joists are as shown in Appendix 2.

The noted cracks measuring about 1mm can then be exposed and repaired using approved resin crack repair compounds and re-plastering done.

The Walls

The cracks appearing on the wall were not structural and were due to the effect of the slab deflection. These can be repaired by re plastering with expanded mesh for aesthetic purposes.

Refer to Sketch No.1 in Appendix 2 for rehabilitation details of the Micro Biology Laboratory.

STRUCTURAL INSPECTION REPORT 4-3 Issue 1.0 / May 2016

4.2 The Kitchen

The defects noted in the Kitchen are due to a ‘knock-on’ effect, meaning they are as a result of one of its walls overloading the Micro biology Lab slab underneath thus causing slab deflection and cracking. The defects noted should be addressed as follows:

The Wall

The cracks measuring approximately 0.5mm appearing on the wall supported on the slab were not structural and were due to the effect of the slab deflection due to overloading.

The adjacent walls also have plaster cracks of approximately 1mm width due to this settlement since the walls are connected. Once the additional supports on the Microbiology Laboratory slab have been fixed, these cracks can be repaired by re plastering with expanded mesh for aesthetic purposes.

Once the underside of the Kitchen slab has been reinforced as described in Section 4.2 above, the 0.5mm width cracks on the finishes can be repaired to prevent any water ingress to the main slab and hence reduce possibilities of leakages into the Micro Biology Lab.

Roof Beams

The 1mm width plaster cracks noted on the beams were not structural. These can be repaired by hacking and re plastering with expanded mesh.

4.3 The Way Forward

The failures developing on the slabs and beams described in Sections 2 to 4 of this report are progressive, meaning they advance or have advanced with time.

As mentioned earlier, interim safety measures by propping of the slabs should be taken and maintained in place until rehabilitation works have been completed.

New supports for these weakened parts of the building have been designed and the schematic drawings are contained in Appendix 2 of this report.

We expect that the contractor will prepare fabrication drawings for the steel work based on these schematic drawings for our approval before construction. However, the contractor will have to re-confirm the dimensions and the exact locations of the main structural members on site before preparing the fabrication drawings.

The Client should arrange for supervision of these rehabilitation works by qualified personnel.

STRUCTURAL INSPECTION REPORT 5-4 Issue 1.0 / May 2016

5 APPENDIX 1

STRUCTURAL INSPECTION REPORT 5-5 Issue 1.0 / May 2016

5.0 The Pharmacy Photos

Plate 5.1.1: A view inside the Pharmacy towards the entrance.

The slab crack of concern is on the panel nearer the door. (See Plate5.1.3 & 4 for details)

Plate 5.1.2: A view inside the Pharmacy towards the back.

STRUCTURAL INSPECTION REPORT 5-6 Issue 1.0 / May 2016

Plate 5.1.3: Crack on the slab panel nearer the door runs across the full width of the room

Plate 5.1.4: Crack on the slab panel nearer the door is directional.

STRUCTURAL INSPECTION REPORT 5-7 Issue 1.0 / May 2016

Plate 5.1.5: Cracks on the slab panel further from the door are not directional. These may be due to deflection of the cracking beam. However since it’s strength is unknown, this panel should be strengthened by providing supporting joists

Plate 5.1.6: Free spanning beam running across the width of the Pharmacy spans 5m.

Cracks near the mid span were noted in 4 places (See Plate 5.1.7, 8 & 9 for crack details)

STRUCTURAL INSPECTION REPORT 5-8 Issue 1.0 / May 2016

Plate 5.1.7: Cracks as seen on the plaster near the mid span of the beam

Plate 5.1.8: Another Crack on the beam near the crack noted above.

STRUCTURAL INSPECTION REPORT 5-9 Issue 1.0 / May 2016

Plate 5.1.9: Another crack on the beam.

These cracks are on a critical part of the beam which suggests beam failure. The plaster was removed to examine the actual structural elements

Plate 5.1.10: Structural elements were exposed by hacking off the plaster to visually examine the extent of the cracks. (See Plate5.1.11 & 12 for crack details)

STRUCTURAL INSPECTION REPORT 5-10 Issue 1.0 / May 2016

Plate 5.1.11: Crack noted on the underside of the RC beam

Plate 5.1.12: Crack extends to the side. The concrete was also observed to be poor in quality as it easily crumbled.

STRUCTURAL INSPECTION REPORT 5-11 Issue 1.0 / May 2016

Plate 5.1.13: Plaster exposed on the crack on the slab panel nearer the door

Plate 5.1.14: The crack was noted to be on the main structural element.

The quality of the concrete also seems poor

STRUCTURAL INSPECTION REPORT 5-12 Issue 1.0 / May 2016

Plate 5.1.15: Slab above the Pharmacy. This wall is the one that lies directly on the slab. Note that it carries the gutter and the roof loads also.

There are also loads from the pedestal and the terrace live loads to the slab. Loading used for the design of the slab is unknown thus it is advisable to reinforce both slab panels of the Pharmacy.

Plate 5.1.16: Cracks were also noted on the finishes above this wall.

These are only on the finishes due to slab deflection

STRUCTURAL INSPECTION REPORT 5-13 Issue 1.0 / May 2016

5.1 Micro-Biology Laboratory Photos

Plate 5.2.1: Entrance to the Micro Biology Lab.

Plate 5.2.2: Inside the Micro Biology Lab

STRUCTURAL INSPECTION REPORT 5-14 Issue 1.0 / May 2016

Plate 5.2.3: There is a crack on the slab that runs across the width of the Lab and extends a little down the wall (See Plate 5.

2. 4, 5 & 6) for crack details)

Plate 5.2.4: At this crack location there is a wall loading the slab at the first floor in the Kitchen

STRUCTURAL INSPECTION REPORT 5-15 Issue 1.0 / May 2016

Plate 5.2.5: The main cracking runs across the width of the Lab

Plate 5.2.6: The main cracking runs across the width of the Lab. The above slab spans 7.4mx4.5m.This is a large span

STRUCTURAL INSPECTION REPORT 5-16 Issue 1.0 / May 2016

Plate 5.2.7: Signs of leakage from the kitchen above. The leak source should be identified and sealed to prevent reinforcement from rusting which may lead to spalling of concrete. The crack noted at the wall/beam is only a plaster crack of a non structural nature

Plate 5.2.8: After hacking off the plaster from the first floor slab, the crack on the structural member was visible. The quality of the concrete works and the plaster was also noted to be poor

STRUCTURAL INSPECTION REPORT 5-17 Issue 1.0 / May 2016

5.2 The Kitchen Photos

Plate 5.3.1: The wall in front in the kitchen rests directly on the slab.

There is no beam support underneath.

This is the cause of the cracks on slab as observe from the Micro Biology Lab below

Plate 5.3.2: There is a crack at the base connection where the wall and slab meet. This is due to deflection of the slab in contact with the rigid wall. There are also cracks at the top of the slab perpendicular to the wall. These are only on the finishes due to the deflection of the slab

STRUCTURAL INSPECTION REPORT 5-18 Issue 1.0 / May 2016

Plate 5.3.3: The settled wall due to the deflection of the slab has caused horizontal plaster cracks at the walls connection.

These cracks are internal only thus not structural.

Detachment of the wall from the ceiling board is also evident

Plate 5.3.4: Vertical crack appear internally on the wall only in one face of the wall. These are plaster cracks that can be repaired with expanded mesh for aesthetic purposes

STRUCTURAL INSPECTION REPORT 5-19 Issue 1.0 / May 2016

Plate 5.3.5: Cracks that appear internally on the wall do not appear externally

Plate 5.3.6: This crack noted above the door opening is non structural, appears internally only and can be repaired the same way as the wall cracks

STRUCTURAL INSPECTION REPORT 6-20 Issue 1.0 / May 2016

6 APPENDIX 2

STRUCTURAL INSPECTION REPORT 6-21 Issue 1.0 / May 2016

6.0 Sketches of Remedial Measures

The following sketches contain the proposed structural schemes that can be applied to the deficient structural elements. These include:

Sketch No.1- Proposed remedial action to be applied at the Micro-Biology Laboratory;

Sketch No.2- Proposed remedial action to be applied at the Pharmacy.

STRUCTURAL INSPECTION REPORT 7-22 Issue 1.0 / May 2016

7 APPENDIX 3

STRUCTURAL INSPECTION REPORT 7-23 Issue 1.0 / May 2016

7.0 Information Supplied by the Client

The following documents were provided by the Client to assist in the structural Audit:

Scheme Architectural layout for existing ground floor slab(used in the audit);

Scheme Architectural layout for proposed new first floor(used in the audit);

Approved Architectural Drawings including:

(a) Site/Block Plans & Schedules(Scheme)

(b) Ground Floor Layout;

(c) First Floor Layout

(d) Elevations 01;

(e) Elevations 02;and

(f) Sections 03.

Approved Structural Drawings including:

(a) Foundation Detail;

(b) RC Slab Detail;

(c) RC Beam;

(d) Columns, Beams & Foundation Detail;

(e) Stairs detail; and

(f) Slab section & Lift Core Detail.

7 day Concrete cube test results for the first floor slab& column;

Fine aggregate grading results;

Test results of concrete blocks.