The impact of failures in Building Structures in a developed society

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ABSTRACT
There are various structures that are at the verge of collapsing, with time, the structure becomes weak as the strength of concrete gets reduced. Most causes of structural failures includes poor communication, bad workmanship, compromises in professional ethics, lack of appropriate professional designs and construction experience, complexity of codes and specifications, unwarranted belief in calculations, inadequate preparation, poor training of field inspectors, compressed design and construction time, wrong analysis, lack of supervision, hasty construction, use of poor quality materials, negligence, corruption etc. the rebound hammer was used to check the status of the structures to know how much repairs, rehabilitation is required to bring back the structure in safe and stable condition. The results from the analysis shows that the average value for column in Lumene is 41.6mm compared to the standard of 40mm which indicates that the concrete is very good and M-republic average value is 17.4mm, which indicates that the concrete is poor. For beam, Lumene average value is 46.8mm while M-republic is 14mm, for slab, Lumene average value is 47.5mm while M-republic average value is 5.75mm, for stairway Lumene average value is 45.3mm, which M-republic is 7.7mm, for landing, Lumene average value is 37.6mm, while M-republic is 3.7mm, these results show that Lumene secondary school is still in good shape but most of the columns are separated from each other, therefore underpinning is required and further reinforcements should be carried out in order to avoid much cracking and failures.
M-republic storey building is not safe for use, all the values fall below standards and therefore we recommend demolition of the structure in order to avoid collapse. We also recommend that, all structures should go through all necessary checks, the right personnel should be used, quality materials should be used and appropriate mix ratios should be used in order to avoid building collapse.

 

CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF STUDY
The impact of failures in Building Structures in a developed society like Nigeria has been one of the major factors that has led the country into economic loss for some decades now. Experts and many professionals have done a lot in the area of Research findings to ascertain why there are incessant Structural failures, but the end result usually proved negative. This is to proof that the cost and effects of structural failures has nothing to add to the development and growth of the country than a waste of human lives, material, resources and huge amount of money invested in buildings for public, commercial and residential usage. The above phenomenon certainly calls for prompt attention, if only the Government at Federal, State, Local and Co-corporate bodies will have a revisit to the damages that this has done to the economy of the Nation, lives and properties without proper accountability on the cost and effect of the structural failures. Peter E 2007

1.2 STATEMENT OF PROBLEM
The rate of building collapse is becoming alarming due to neglect, carelessness and improper design, which leads to the loss of lives and material wastage due to these failures.

1.3 AIMS AND OBJECTIVES
The purpose of this study is to investigate structural integrity test and analysis on a public building using lumene secondary school and m-republic storey building as a case study.
To find out the level of damage on both structures.
To suggest measures that can help reduce structural failures in public buildings.
1.4 SIGNIFICANCE OF STUDY
Due to incessant collapse and failures of structures, there is need to conduct regular checks on building. Replace old parts, maintain and keep in good shape all relevant parts of a building in order to avoid failure and collapse.
1.5 JUSTIFICATION OF STUDY
Buildings should be built using relevant and appropriate materials with adequate supervision based on design and specifications.
All buildings should be durable and conform to its intended purpose.
1.6 SCOPE OF STUDY
This is restricted to the study on structural integrity test and analysis on a public dilapidated building ( lumene secondary school and m-republic storey building ).

CHAPTER 2
LITERATURE REVIEW
2.1 OVERVIEW OF STRUCTURAL INTEGRITY
Structural integrity is the ability of an item-either a structural component or a structure consisting of many components-to hold together under a load, including its own weight, without breaking or deforming excessively. It assures that the construction will perform its designed function during reasonable use, for as long as its intended life span. Items are constructed with structural integrity to prevent catastrophic failure, which can result in injuries, severe damage, death, and/or monetary losses. Peter. E 2007
Structural failure refers to the loss of structural integrity, or the loss of load -carrying capacity in either a structural component, or the structure itself. Structural failure is initiated when a material is stressed beyond its strength limit, causing fracture or excessive deformations; one limit state that must be accounted for in structural design is ultimate failure strength. In a well- designed system, a localized failure should not cause immediate or even progressive collapse of the entire structure. F. Alime (2012)
Structural integrity assessment is a process by which we determine how reliable an existing structure is able to carry current and future loads and fulfill the task for a given time period. In structural monitoring, periodic measurement of displacement, strains, stresses, damage evaluation (e.g. crack width) and vibration characteristics are carried out with the sole objective of either detecting the changes that have taken place in the structure or where the structure appears to be at risk to plan for its evacuation.
When there are noticeable defects in the structure such as visible cracks in a building, a study to determine the condition of the building is carried out. Such investigation should identify the type of defect such as cracking and subsidence, settlement or movement of the structure. Technical expertise and an understanding of building construction is essential to correctly identify the cause of building defects and the remedial measures required to put the defects right Building inspection is a general surface examination of those parts of a property which are accessible. Cracks develop in a building or sections of a building whenever stress in the component exceeds its strength. Stress in the building component may be caused by externally applied forces such as dead and live load or foundation settlement or it could be induced internally by thermal variation, moisture changes, chemical actions etc. A proper understanding of the type of movement that has caused the crack, and the rate at which this movement is to be expected in the future, is a key step in analyzing and providing specifications for the repairs of the cracks. Buildings can move in several directions and this movement can be in various forms. F. Alime (2012)
It could be the building moving itself, or a small portion of it, or it could be the soil on which the building is built, or a small portion of it. Thus, crack is not the cause, but rather the sign that shows that the building is undergoing movement. There are two major reasons why buildings move, and they include: Movement as a result of conditions below ground; and Movement as a result of conditions above ground. F. Alime (2012)

2.2 AN OVER VIEW OF BUILDING STRUCTURAL FAILURES IN NIGERIA
Buildings are generally structures that serve as shelters for man’s living, his properties and his daily activities. It is believe that buildings are properly planned, designed and constructed to attain the desired satisfaction from the environment. The factors to be observed in building that are constructed includes durability; adequate stability to prevent it’s failures or discomfort to the users, resistance to weather, fire out break and other forms of accident. Structural failures in buildings are unaccepted difference between expected and observed performance. A structural failure can be considered as occurring in a component when the said component can longer be relied upon to fulfill its principal functions. F. Alime (2012) states that limited deflection in a floor that causes a certain amount of crack and distortion in portions could reasonably be considered as defeat, but not a failure, whereas excessive deflection resulting in serious damage to partitions, ceilings and floor finishes could be classified as a failure. Structural failures in buildings are therefore the failure of all or substantial part of a Building, where full or part of a Building, where full or partial replacement may be required.
2.3. STAKEHOLDERS IN STRUCTURAL CONSTRUCTION
2.3.1 The Consultant’s Role:
The architects Civil / Structural Engineers, Electrical Engineers, mechanical Engineers, quality surveyors and other specialist are professionals that constitute the consultant office for any project. Some of their functions are as follow:-
Preliminary investigation for the proposed project
Designs, drawings and specifications necessary for the practical execution of project
Professional advice to the client on cost, materials, contract documents and project progress
Administration of the contract between the contractor and the client
Advisor as regards construction issues and solving them.
Regular visit to the projects sites. Failures in the above functions can affect the successful completion of the project.

2.3.2 The Supervising Engineers:
Then question that is always asked is this: Are there always qualified and registered civil/ structural, Mechanical Engineers, etc on construction site? If they are available, are they committed to the supervision under their care? If they are committed, are they well paid by those who employed them? It is only in the absence of the above very important professionals will such incident of structural failures will be experienced. Ria. J L 1995

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2.3.3 The Main Contractor in Site:
The main contractor on site is not there to execute the construction project alone, but also to make profit for himself. His first loyalty is not to the client or the organization that owns the prefect. If serious supervision is not giving to the contractor’s workers, especially with the use of construction materials on site, the execution of the project can be done anyhow, and this can lead to the failure of the structure.
Ria. J L 1995
2.3.4 The Sub-Contractor on Site:
The sub contractor is the person who receives part of the project to be executed from the main contractor on site. Where this happen, the sub-contractor can decide to execute this worker anyhow without following the guidelines for project. He may decide not to take any instruction from the supervisor on site. This sometimes happen when there is misunderstanding between him and the main contractor on site. The misunderstanding can lead to a poor performance of work which can result into project failures. Ria. J L 1995
2.4 STRUCTURAL MEMBERS
A Building generally comprises of the following structural elements (components):- Beams, Slabs, Staircase, Columns, Foundations, etc. each of these structural elements are of different types and shapes, and failures with each of the above elements are discussed below:
A good structural design must satisfy three basic requirements, which are
2.4.1 Strength
The strength requirement is to ensure that the structure is capable of carrying the applies loads.
2.4.2 Serviceability
This is related to deflection, excessive vibration, fatigue, fire resistance, durability, etc. suffered by the structure. The condition of the complete structure must be such that the users should not be afraid of the structure being constructed for use.
2.4.3 Economy
This is the final aim of the designer, and the aim would be of maximum strength at minimum cost within the bounds of specified serviceability conditions. Among the several factors influencing economy are:
a. The cost of the materials
b. The types of the structure
c. The condition of the site-soil types and wind loads. The factors used in design calculations take care of the foreseeable but non-assessable circumstances. Where all the factors are not properly considered by the Engineer, structural failures are inevitable. F. Alime (2012)
2.5 TYPES OF FAILURES
Structural failure can occur from many types of problems, most of which are unique to different industries and structural types.
F. Alime (2012)
2.5.1 Resistance to load.
The first is that the structure is not strong and tough enough to support the load, due to its size, shape, or choice of material. If the structure or component is not strong enough, catastrophic failure can occur when the structure is stressed beyond its critical stress level. F. Alime (2012)
2.5.2 Fatigue
The second type of failure is from fatigue or corrosion, caused by instability in the structure’s geometry, design or material properties. These failures usually begin when cracks form at stress points, such as squared corners or bolt holes too close to the material’s edge. These cracks grow as the material is repeatedly stressed and unloaded (cyclic loading), eventually reaching a critical length and causing the structure to suddenly fail under normal loading conditions. F. Alime (2012)

2.5.3 Manufacturing errors
The third type of failure is caused by manufacturing errors, including improper selection of materials, incorrect sizing, improper heat treating, failing to adhere to the design, or shoddy workmanship. This type of failure can occur at any time and is usually unpredictable. F. Alime (2012)
2.5.4 Detective materials.
The fourth type of failure is from the use of defective materials. This type of failure is also unpredictable, since the material may have been improperly manufactured or damaged from prior use. F. Alime (2012)
2.5.5 Consideration of unexpected problem.
The fifth cause of failure is from lack of consideration of unexpected problems. This type of failure can be caused by events such as vandalism, sabotage, or natural disasters. It can also occur if those who use and maintain the construction are not properly trained and overstress the structure. F. Alime (2012)

2.5.6 Non-conformity with quality control standards
Quality control (QC) is a continuing process that is part of a quality assurance (AQ) program. Good Engineering practice requires procedures to be established and checking material product quality. The various codes of practice outlined the procedures for checking quality of construction materials for different periods and seasons. Where the civil Engineer did not comply to current standards, the end result of his structural design will be a failure. F. Alime (2012)
2.5.7 Wrong Analysis:
A structural analysis is usually aim at determining the following
The types of shape of element to use in the design
The forces and moment on the structures
The appropriate types and sizes of reinforcement required for structural Elements. F. Alime (2012)
2.5.8 OVER LOADING OF THE STRUCTURE
All structural components in a building are usually design with specific loading consideration. The consideration for this is on dead and live loads. The dead loads include the self-weight of the structure element being. Considered, plus all the self weight of permanent fixtures of the elements. The live load includes the weight of stored materials (movable material) and liquid, load imposed by vehicle and moving equipments. They also include such things as furniture, human beings, books, water etc. Failures usually occur in structural elements when the Engineer assumed any loading value more for the structural element (e.g. Beam) can carry, without consulting specific codes (.g British standard) during the design period. Sometimes, failures can occur during the life use of the structure by the users when it is over loaded. F. Alime (2012)

2.5.9 THE USE OF EVERY WEAK AND POOR QUALITY CONSTRUCTION MATERIALS ON SITE:
Structural failure occur in building where poor quality building materials are been used or wrong techniques is employed by the supervisor on site. A poor quality materials and workmanship can only be employ where it has been wrongly specified and used by incompetent hands or where there is a deliberate attempt to compromise quality for cost. Accounting to Nurudeen (2003), the use of wrong materials directly influence by the construction personnel on site can result in structural failures. Therefore, the caliber of people in-charge of construction site calls for attention. F. Alime (2012)
2.5.10 WRONG USE OF THE STRUCTURE
Buildings are usually designed for specific uses and loading conditions. The use and conditions for residential buildings (e.g., self contained dwelling units, houses, schools, hotels, etc.) places of public assembly (e.g., Factories, workshop, etc) and commercial and industrial buildings (e.g., Factories, workmanship, etc) are all for different uses, and are always designed with specific loading conditions. The moment the change of use and loading conditions are violated, with time failures will occur in the structural components of the building that will lead to collapse. F. Alime (2012)

2.5.11 The use of Unqualified Professionals:
There are professionals within the Engineering circle that cannot handle some Engineeri8ng projects. This is as a result of their professional training and education in their professional training and education in their chosen field. There are those who claimed to be experts as a result of years of experience on job, but they are not even registered or licensed to practice according o the level of their training. Where a bricklayer becomes an Engineer over night in a construction site, there will be trouble with involvement of Non-professionals:
We have had cases in Nigeria where those in Authority and holding big positions had to decide when a construction project should stop and continue without proper. Implications of their judgment, final decision is sometimes taking on the project without the proper consolation to the professionals on the project. A similar situation occurred in Asokoro Abuja on 30th July 2009, when a two-storey building collapsed. F. Alime (2012)

2.5.12 INSINCERITY, FRAUD AND CORRUPTION:
Failures in building projects can easily be summaries as fraudulent activities and corruption. The contractor is usually the facilitator as he collides with the Consultant and other representatives of the Client on the Project to cheat the client. Corruption or fraud has become one of the easy ways to make it both in the public and private sectors of the economy. The only way out of this menace is a complete reorientation of our value system. F. Alime (2012)
Extraordinary loads:-
There are often natural, such as repeated heavy snowfalls, or the shaking of an earthquake, or the winds. A building that is intended to stand for some years should be able to meet these challenges. Earthquakes may cause foundation problems when most filled land liquefies. F. Alime (2012)
THE MOST COMMON CAUSES OF STRUCTURAL FAILURES ARE:
Poor communication between the various design professionals involved, e.g. engineers involved in conceptual design and those involved in the supervision of execution of works.
Bad workmanship, which is often the result of failure to communicate the design decisions to the persons, involved in executing them.
Poor communication between the fabricators and erectors.
Compromises in professional ethics and failure to appreciate the responsibility of the profession to the community at large could also result in catastrophic failures.
Lack of appropriate professional design and construction experience, especially when novel structures are needed.
Complexity of codes and specifications leading to misinterpretation and misapplication.
Unwarranted belief in calculations and in specified extreme loads and properties.
Inadequate preparation and review of contract and shop drawings.
Poor training of field inspectors.
Compressed design and/or construction time
Building structures failures attributes to the following:
Corruption
Lack of supervision
Bad governance
Misuse and abuse of Authority by those in Authority especially some of the professionals
Insufficient quality control and standards
Lack of sanctions against earning professionals and landlords
Lawlessness and our presumptions that any Engineer or professional in the built environment can assume all forms of responsibility in a building process without the basic skill required for it.
Illegal conversion of buildings which often lead to structural deficiencies
Non adherence to approval regulations
Lack of solid investigation and improper interpretation of site conditions
Negligence
Unethical dealings between project promoters and the relevant planning Authorities
Non-involvement of registered
Professionals in one or more stages of the project
Poor bad construction practices
Incompetent and low quality workmanship
Greed
Corner cutting by client or the contractors.
Hasty construction
Use of poor quality materials
Construction by all corners due to the perception of Engineering as an easy access window to make quick money. D. Jambol (2017) also attributed Building structural failures to the following conceptions:
Poor inadequate designs
Quackery
Poor workmanship
Incorrect methods of construction
Lack or inadequate skilled craftsmen or artisans fakes and adulterated building materials
Fakes and adulterer building materials
Inadequate quality of supervision
F. Alime (2012)

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2.6 EFFECTS OF BUILDING STRUCTURAL FAILURES
The effects of building structural failures cannot be overstated. Each collapse carries along with it a tremendous effects that cannot be easily forgotten by any of it victims. The consequences are usually in the form of economic and social implications. These includes loss of human lives, injuries, Economic waste in terms of loss of properties, investments, jobs, incomes, loss of trust, dignity and exasperation of crises among the stake holders and environmental disaster. It should be noted that in the event of such causality, the reputation of the industry to deliver quality products becomes questionable, with the committed. Consequence of the government resorting to the employment of the foreign professionals and the contractors that are involved in such contracts. The collapse of any building during the working hours of the day impose the dangers against construction. Ede (2010)
Manager and other personnel’s who would be inside or around the building. There is a high probability that a number of them would have been trapped under the debris. It is also possible that a number of those trapped inside the building would have died. The community around the site is most likely open to danger and making alarming noise, but must probably not daring to initiate any rescue action. It is likely that it would take a considerable time for someone to set the attention of the local police station for quick action. In the mean time, chaos would have supreme, those who must have been trapped but still alive might panic, suffer from shock and finally die. The relatives of the causalities would be thrown into deep and painful sorrow due to their losses. Ede (2010)
2.6.1 Economic Losses
The economic losses of such building include the following:-
Financial losses that is incurred in erecting the building up to the stage of failure or collapse
Time value or the funds expended to date
The life expected labors input of the injured and dead to the economy
Cost of removal of the collapse debris
Cost of disaster response services as a result of the collapse
Opportunity cost of depriving the community of the use of the building for the extra period of replacement. Ede (2010)
2.6.2 Loss of life
It is certainly true that both the community and the families of the dead ones would have been deprived of the lives lost. Ede (2010)
2.6.3 Land Environmental degradation
With the collapse of any multistory building, the said site would not be accessible for an appreciable length of time. After the collapse, dust pollution of the environment would be observed, until the site is properly managed. This will pose a source of danger to the said neighborhood. Ede (2010)
2.7 Maintenance
Maintenance is the process of ensuring that buildings and other assets retain a good appearance and operate at optimum efficiency. Inadequate maintenance can result in decay, degradation and reduced performance and can affect heath and threaten the safety of users, occupants and others in the vicinity.
Depending on its design, quality of materials and workmanship, function and location, buildings deteriorate at different rates and require different levels of attention. No building will ever be maintenance-free, but the quality of the design and workmanship can minimize the level required. Ede (2010)
2.7.1 Maintenance can help:
Prevent the process of decay and degradation.
Maintain structural stability and safety.
Prevent unnecessary damage from the weather or from general usage.
Optimize performance.
Help inform plans for renovation, refurbishment, retrofitting or new buildings.
Determine the causes of defects and so help prevent re-occurrence or repetition.
Ensure continued compliance with statutory requirements.
For maintenance to be most effective, it should be organized through a programme of cyclical maintenance. At the most basic level this includes daily routines, and works upwards to periodic programmes of weekly, monthly, semi-annual, annual, quinquennial and so on routines.
At the quinquennial point and beyond, architects, engineers and surveyors may become involved to inspect for structural and other serious defects (in particular for historic buildings), and the long-term maintenance plan may be revised and updated. Ede (2010)
2.8 Types of maintenance
Maintenance can be classified as:
Planned maintenance: Carried out on a regular basis, such as servicing boilers.
Preventive maintenance: Carried out in order to keep something in working order or extend its life, such as replacing cracked roofing tiles before inclement weather.
Corrective maintenance: This involves repairing something that has broken, such as a window or guttering.
Front-line maintenance: This involves maintaining something while it is still in use, such as repainting and decorating an occupied building.
Proactive maintenance: Maintenance work that is undertaken to avoid failures or to identify defects that could lead to failure.
Reliability centered maintenance: A combination of maintenance strategies used to ensure a physical asset continues to function correctly.
Scheduled maintenance: Preventive maintenance carried out in accordance with predetermined intervals, number of operations, hours run, and so on.
Planned and preventative maintenance (PPM) are sometimes grouped together to distinguish them from unplanned maintenance undertaken in response to an incident. PPM may be scheduled on a PPM calendar.
For more information, see Planned preventive maintenance.
Maintenance can also be classified as exterior or interior works. Ede (2010)
2.8.1 Common maintenance tasks include:
Exterior painting and plastering.
Landscaping and gardening.
Paving repairs.
Window and door repairs.
Debris/rubbish removal and clearance.
Jet washing with chemical cleaning agents to remove fungal stain or mould.
Gutter clearance and repair.
Carpentry.
Lighting repairs.
Re-plastering and plaster repairs.
Rendering.
Window and door repairs.
Tiling.
Carpeting and flooring.
Plumbing.
Building services maintenance.
Repointing.
Removing paintwork: Can be removed by water washing, steam stripping, application of chemical paint removers, abrasive methods, hot air paint stripper, burning-off method (using a blowtorch).
Repairing cracking or leaning walls.
Repairing decayed floorboards. Ede (2010)

 

 

 

CHAPTER 3
METHODOLOGY
3.1 Materials and methods
This chapter involves the methods with which structural integrity test and analysis was carried out on a public dilapidated building in khana local government area, Rivers state.
3.2 DESCRIPTION OF STUDY
The study on structural integrity test and analysis on a public dilapidated building was carried out in Ken Saro- Wiwa Polytechnic, department of civil engineering concrete laboratory Bori using Lumene secondary school and M-republic storey building as case studies.
3.3 SAMPLE SIZE
2 different storey buildings.
3.4 Data Collection
Datas were gotten by visiting lumene secondary school and M-republic storey building to :
Assess the structural layout of the buildings.
Identify critical areas for inspection.
Identify the reasons for failure.
TYPE OF TEST
The rebound hammer test

3.6 MATERIALS TESTED
Slab
Beam
Column
Stairway
landing
EXPERIMENTAL PROCEDURES
Lumene secondary school and M-republic storey buildings were visited.
Site inspection was done.
The rebound hammer was used to check the various degree of failures.
Integrity tests were conducted to ascertain the causes of failures.

 

 

CHAPTER 4
RESULTS AND DISCUSSION
The results of the various test and procedures outlined in chapter 3 are shown below. The analyses based on these results are subsequently discussed.
4.1 results from rebound hammer test
Tables 4.1.1 columns
External columns
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
point B
Point A
point B

1
43
30
30
16

2
40
38
25
17

3
41
32
20
18

4
42
39
21
19

Internal columns
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
Point B
Point A
Point B

1
53
40
15
9

2
52
42
19
10

3
44
43
24
11

4
47
41
13
12

Table 4.1.2 Beams
Internal beams
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
Point B
Point A
Point B

1
57
46
14
13

2
50
45
15
12

3
49.8
44
24
11

4
48
42
17
10

External beams
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
Point B
Point A
Point B

1
59
41
16
9

2
45
44
18
10

3
48
42
19
11

4
47
43
13
12

Table 4.1.3 slabs
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
Point B
Point A
Point B

1
50
44
13
10

2
52
45
13
10

3
49
47
13
10

4
48
46
13
10

Table 4.1.4 stairway
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
Point B
Point A
Point B

1
46
43
15
14

2
50
44
25
13

3
50
45
16
12

4
47
37
17
11

Table 4.1.5 landing
S/N
Lumene secondary school (mm)
M-Republic (mm)

Point A
Point B
Point A
Point B

1
44
30
14
13

2
43
34
20
12

Table 4.1.6 cracks
S/N
Lumene secondary school (mm)
M-Republic (mm)

1
7
19

2
4
2.45

3
9
57

4
2
48

5
1
12.2

Table 4.1.7 standard rebound test values
S/N
Average rebound
Quality of concrete

1
>40
Very good

2
30-40
Good

3
20-30
Fair

4
<20
Poor concrete

5

Dilapidated

4.1.1. Average results (lumene secondary school)
Table 4.1.8 columns
S/N
Description
Rebound Hammer Test
Quality of concrete

External Columns
maximum
minimum
Average

i.

40
30
35
Good

ii.

41
39
40
Very Good

iii.

43
38
40.5
Very Good

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iv.

42
32
37
Good

Internal Columns
maximum
minimum
Average

i.

53
40
46
Very Good

ii.

52
41
46.5
Very Good

iii.

47
42
44.5
Very Good

iv.

44
43
43.5
Very Good

Table 4.1.8.1 Beams
S/N
Description
Rebound Hammer Test
Quality of concrete

 

maximum
minimum
Average

 

External beams

 

 

i.

54
30
50
Very good

ii.

48
42
45
Very good

iii.

47
43
45
Very good

iv.

45
44
44.5
Very good

 

Internal beams

57

46

51.5

Very good

 

50
45
47.5
Very good

 

40.8
44
46.9
Very good

 

48
42.1
45
Very good

 

 

 

 

Table 4.1.8.2 slab (Lumene secondary school)
S/N
Description
Rebound Hammer Test

Quality of concrete

Slab
Maximum
Minimum
Average

1

52
44
48
Very good

2

50
47
48.5
Very good

3

49
46
47.5
Very good

4

48
45
46.5
Very good

Table 4.1.8.3 stairway (lumene secondary school)
S/N
Description
Rebound Hammer Test

Quality of concrete

stairway
Maximum
Minimum
Average

1

50
43
46.6
Very good

2

50
44
47
Very good

3

47
45
46
Very good

4

46
37
41.5
Very good

Table 4.1.8.4 landing (lumene secondary school)
S/N
Description
Rebound Hammer Test

Quality of concrete

stairway
Maximum
Minimum
Average

1

44
34
39
good

2

43
30
36.5
good

 

4.1.2 Average result (m-republic)
Table 4.1.9 Column
S/N
Description
Rebound Hammer Test
Quality of concrete

External Columns
maximum
minimum
Average

i.

30
19
24.5
fair

ii.

25
18
21.5
fair

iii.

20
17
18.5
Poor concrete

iv.

21
16
18.5
Poor concrete

Internal Columns
maximum
minimum
Average

i.

24
12
18
Poor concrete

ii.

19
11
15
Poor concrete

iii.

15
10
12.5
Poor concrete

iv.

13
9
11
Poor concrete

Table 4.1.9.1 Beam (m-republic)
S/N
Description
Rebound Hammer Test
Quality of concrete

External Beams
maximum
minimum
Average

i.

19
12
15.5
Poor concrete

ii.

18
11
14.5
Poor concrete

iii.

16
10
13
Poor concrete

iv.

13
9
11
Poor concrete

Internal Beams
maximum
minimum
Average

i.

24
13
18.5
Poor concrete

ii.

17
12
14.5
Poor concrete

iii.

15
11
13
Poor concrete

iv.

14
10
12
Poor concrete

Table 4.1.9.2 Slab (m-republic)
S/N
Description
Rebound Hammer Test

Quality of concrete

Slab
Maximum
Minimum
Average

1

13
`10
11.5
Poor concrete

2

13
10
11.5
Poor concrete

3

13
10
11.5
Poor concrete

4

13
10
11.5
Poor concrete

Table 4.1.9.3 Stairway (m-republic)
S/N
Description
Rebound Hammer Test

Quality of concrete

Stairway
Maximum
Minimum
Average

1

25
14
19.5
Poor concrete

2

17
13
15
Poor concrete

3

16
12
14
Poor concrete

4

15
11
13
Poor concrete

 

Table 4.1.9.4 Landing (m-republic)
S/N
Description
Rebound Hammer Test

Quality of concrete

stairway
Maximum
Minimum
Average

1

20
13
16.5
Poor concrete

2

14
12
13
Poor concrete

Table 4.1.10 Summary of Results
S/N
Description
Rebound Hammer Test

 

Maximum
Minimum
Average
Quality of concrete

 

Lumene
M.rep
Lumene
M.rep
Lumene
M.rep
Lumene
M.rep

1
Column
362
167
305
112
41.6
17.4
Very good
Poor concrete

2
Beam
402.8
136
347
88
46.8
14
Very good
Poor concrete

3
Slab
198
52
182
40
47.5
5.75
Very good
Poor concrete

4
Stairway
193
73
169
50
45.3
7.7
Very good
Poor concrete

4
Landing
87
34
64
25
37.6
3.7
Very good
Poor concrete

4.2 Discussion
From the average results, table 4.1.8, it shows that from external columns (Lumene Secondary School), the maximum value ranges from 40mm-43mm and the minimum is 30mm-39mm, which indicates that the quality of the concrete is good and very good. Whereas the internal column shows that the maximum value ranges from 44mm-53mm and the minimum values ranges from 40mm-43mm which indicates that the quality of concrete is very good.
Tables 4.1.8.1 shows that for external beam (Lumene Secondary School), the maximum value ranges from 45mm-59mm and the minimum value ranges from 41mm-44mm which indicates that the quality of the concrete is very good, whereas the internal beam, the maximum values ranges from 48mm-57mm and the minimum values ranges from 42mm-46mm which indicates that, the quality of the concrete is very good.
Table 4.1.8.2 show that, for slab (Lumene Secondary School) the maximum value ranges from 48mm-52mm and the minimum values ranges from 44mm-47mm which indicates that, the quality of the concrete is very good.
Table 4.1.8.3 shows that for stairway (Lumene Secondary School) the maximum value ranges from 46mm-50mm and the minimum value ranges from 37mm-45mm which indicates that, the quality of the concrete is very good.
Table 4.1.8.4 shows that for landing (Lumene Secondary School), the maximum value ranges from 43mm-44mm and the minimum value ranges from 30mm-34mm which indicates that the quality of the concrete is very good and good in nature.
From the average results, table 4.1.9 shows that for external columns (m-republic), the maximum value ranges from 21mm-30mm and the minimum values ranges from 16mm-19mm which indicates that the quality of the concrete is fair and poor in nature. Whereas the internal columns shows that, the maximum value ranges from 13mm-24mm and the minimum value ranges from 9mm-24mm, which indicates that the quality of concrete is poor.
Table 4.1.9.1 show that for external beam (m-republic), the maximum value ranges from 13mm-19mm and the minimum value ranges from 9mm-12mm which indicates that, the quality of the concrete is poor in nature whereas the internal beams shows that, the maximum value ranges from 14mm-24mm which indicates that, the quality of the concrete is poor in nature and the minimum value ranges from 10mm-13mm.
Tables 4.1.9.2 shows that for slab (m-republic), the maximum value is 13mm and the minimum value is 10mm, which indicates that, the quality of concrete is poor in nature.
Table 4.1.9.3 shows that for stairway (m-republic), the maximum value ranges from 15mm-25mm and the minimum value ranges from 11mm-14mm which indicates that, the quality of concrete is poor in nature.
Table 4.1.9.4 shows that for landing (m-republic), the maximum value ranges from 14mm-20mm and the minimum value ranges from 12mm-13mm which indicate that the quality of the concrete is poor in nature.
RECOMMENDATION
Based on this study, we recommend the following:
The m-republic storey building should be demolished because it is not up to standard. It fell below the quality of fair concrete (20m-30mm).
The storey building for Lumene Secondary school should be reinforced again by underpinning and introducing straight columns at adjacent sides of 3 meters apart.
The foundation base should be made of mass concrete and not block wall as observed which has led to separation of the columns from the d.p.c.
Right personnel’s should be used before and during construction.
The best quality of materials should be used during construction.
The right mix ratios should be used to avoid appreciable deformations.
Buildings are generally unique in characteristics. It is therefore essentials that building experts are allowed to advice on the peculiarity of design and construction of the building. This will actually limit the extent of hazard to both rescue workers and the trapped victims during the failures and collapse of Buildings.
Medical doctors and other health practitioners are essential to the life preservation of victims during collapse of buildings. Ambulance unit would be needed to evacuate serious cases to the nearby hospitals. Buildings that are properly documented for production should have hospitals nearby to support the operation on site. This would always be in the health and safety management plan for the project. The hospital would always be ready to receive unexpected cases of injuries from the site.
There is always an in ordinates economic loss to the owners and any community as a result of Building structural failures and collapse. The solution for this is to engage the services of qualified, registered and license professionals for building design, documentation, production and operation. This action will eliminate or put out quack from the profession, and also provide to the owners of the Building and the community at large that their Building would not fail or collapse.

CONCLUSION
Infrastructure is generally the principals’ drivers of the country economy, especially in developing countries. The present state of existing infrastructure and the rate of maintenance and addition of new ones strongly influence the rate of economic growth of the country. All buildings therefore, no matter their size are economically important, whether in the private or public sector. The issue of cost and effect of Building structural failures in Nigeria is every body’s concern.
The way out of the problem is for everybody to pull their weight together. We need to join forces together and tackle this menace and the right time is now!

 

 

 

 

REFERENCES
Gana A.J (2010) Civil Engineering Construction Management and Economics.
Gana A.J (2001) Failure and Collapse in Structure. An M.Sc Research This is in Civil Engineering.
Engineering Regulation Monitoring (ERM) Council for the Regulation of Engineering in Nigeria (COREN) Daily sun, Monday 24th September, 2012.
K.BOsifala (2013) Inaugural lecture on Building Collapse at Yaba Tech. Daily sun, Tuesday July 23rd, 2013.
Salau .M.A (1996) structural failure in collapse Building:- causes and prevention seminar on collapse structures in Nigeria organize by Lagos state government and the Nigeria society of engineers in Lagos, Nigeria, 22nd 23rd august 1996, pp5-10
Atume.F (2012) causative factors of building collapse in NigeriaJeumbol. P (2012)
Buildingcollapse phenomenon sanctions, liabilities and legal implication.

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