A Study of Building Cracks on Wall Specifically on Elastic Deformation, Thermal Movement, Shrinkage
CHAPTER ONE
Objective of the study
The primary objective of this study is to comprehensively investigate and analyze the factors of elastic deformation, thermal movement, and shrinkage as they relate to building wall cracks. The study aims to achieve the following specific objectives:
- To delve into the underlying mechanisms by which elastic deformation, thermal movement, and shrinkage contribute to the initiation and propagation of cracks in building walls.
- To quantify the interactions and synergistic effects that may occur when multiple factors elastic deformation, thermal movement, and shrinkage act simultaneously.
- To identify the specific areas within building structures that are most susceptible to cracks due to elastic deformation, thermal movement, and shrinkage.
CHAPTER TWO
REVIEWED OF RELATED LITERATURE
Building cracking
Building cracking is a common phenomenon in construction and structural engineering, often arising due to various internal and external factors. Understanding the causes, mechanisms, and mitigation strategies for building cracking is essential for ensuring the safety, durability, and aesthetic appeal of structures.
Building cracking refers to the development of fractures or discontinuities in building materials, leading to compromised structural integrity and aesthetic concerns. Cracks can occur in different parts of a building, including walls, floors, ceilings, and foundations. While some cracks are harmless and result from natural material behavior, others can indicate serious structural issues that require prompt attention.
- Causes of Building Cracking Multiple factors contribute to building cracking, ranging from environmental conditions to construction practices. These include:
- Elastic Deformation: External loads, such as live and dead loads, can induce stress that exceeds the material’s elastic limit, resulting in deformation and cracking (Popovics et al., 2003)
- Thermal Movements: Temperature fluctuations cause building materials to expand and contract, generating internal stresses that lead to cracking (Kearsley et al., 2010)
- Shrinkage: Drying and curing processes can cause materials like concrete to shrink, resulting in cracks (Neville, 2004)
- Settlement: Uneven settling of foundations or soil can create differential movements in a building, leading to cracks (Wardhana et al., 2017)
- Chemical Reactions: Some chemical reactions, like alkali-silica reaction in concrete, can cause expansion and cracking (Dhir et al., 2004)
- Mechanisms of Building Cracking Building cracking mechanisms can be categorized based on their underlying causes:
- Tensile Cracking: Tensile stresses perpendicular to the crack surface lead to opening of cracks due to inadequate structural design or excessive loading (Mehta et al., 2006)
- Shear Cracking: Shear forces result in diagonal or horizontal cracks, often observed near load-bearing elements like columns and beams (Trahair et al., 1992)
- Flexural Cracking: Bending stresses cause cracks in beams and slabs, particularly where the material is weak in tension (ACI Committee 224, 2001)
- Diurnal Thermal Cracking: Temperature-related expansion and contraction induce cracks, especially in concrete and masonry structures (Matthys, 1997)
- Mitigation and Prevention Strategies Mitigating building cracking involves a combination of design, material selection, and construction techniques:
- Proper Design: Structural engineers can ensure adequate reinforcement, proper load distribution, and appropriate expansion joint placement to prevent excessive stress and deformation (Hobbs et al., 2019)
- Material Selection: Using materials with low coefficients of thermal expansion and appropriate shrinkage characteristics can minimize cracking (ACI Committee 224, 2001).
- Controlled Curing: Proper curing techniques, such as moisture retention and avoiding rapid drying, can reduce shrinkage-related cracks (Neville, 2004).
- Joint Design: Incorporating expansion and control joints accommodates thermal movement and prevents uncontrolled cracking (Kearsley et al., 2010)
- Quality Construction: Ensuring proper compaction, adequate reinforcement, and precision in construction practices reduces the likelihood of cracking (Soutsos et al., 2014).
CHAPTER THREE
RESEARCH METHODOLOGY
INTRODUCTION
In this chapter, we described the research procedure for this study. A research methodology is a research process adopted or employed to systematically and scientifically present the results of a study to the research audience viz. a vis, the study beneficiaries.
RESEARCH DESIGN
Research designs are perceived to be an overall strategy adopted by the researcher whereby different components of the study are integrated in a logical manner to effectively address a research problem. In this study, the researcher employed the survey research design. This is due to the nature of the study whereby the opinion and views of people are sampled. According to Singleton & Straits, (2009), Survey research can use quantitative research strategies (e.g., using questionnaires with numerically rated items), qualitative research strategies (e.g., using open-ended questions), or both strategies (i.e., mixed methods). As it is often used to describe and explore human behaviour, surveys are therefore frequently used in social and psychological research.
CHAPTER FOUR
DATA PRESENTATION AND ANALYSIS
INTRODUCTION
This chapter presents the analysis of data derived through the questionnaire and key informant interview administered on the respondents in the study area. The analysis and interpretation were derived from the findings of the study. The data analysis depicts the simple frequency and percentage of the respondents as well as interpretation of the information gathered. A total of eighty (80) questionnaires were administered to respondents of which only seventy-seven (77) were returned and validated. This was due to irregular, incomplete and inappropriate responses to some questionnaire. For this study a total of 77 was validated for the analysis.
CHAPTER FIVE
SUMMARY, CONCLUSION AND RECOMMENDATION
5.1 Introduction
It is important to ascertain that the objective of this study was to ascertain a study of building cracks on wall specifically on elastic deformation, thermal movement, shrinkage. In the preceding chapter, the relevant data collected for this study were presented, critically analyzed and appropriate interpretation given. In this chapter, certain recommendations made which in the opinion of the researcher will be of benefits in addressing a study of building cracks on wall specifically on elastic deformation, thermal movement, shrinkage
Summary
This study was on a study of building cracks on wall specifically on elastic deformation, thermal movement, shrinkage. Three objectives were raised which included; To delve into the underlying mechanisms by which elastic deformation, thermal movement, and shrinkage contribute to the initiation and propagation of cracks in building walls, to quantify the interactions and synergistic effects that may occur when multiple factors elastic deformation, thermal movement, and shrinkage act simultaneously and to identify the specific areas within building structures that are most susceptible to cracks due to elastic deformation, thermal movement, and shrinkage.. A total of 77 responses were received and validated from the enrolled participants where all respondents were drawn from selected construction companies in Lagos state. Hypothesis was tested using Chi-Square statistical tool (SPSS).
Conclusion
In conclusion, this comprehensive study has delved into the intricate realm of building cracks on walls, focusing specifically on the significant factors of elastic deformation, thermal movement, and shrinkage. The insights gleaned from this research underscore the critical importance of understanding these mechanisms in ensuring the structural integrity, safety, and longevity of building structures.
The analysis of elastic deformation revealed the complex interplay between external loads and material response, elucidating how stress accumulation can lead to deformation and, subsequently, crack formation. By recognizing the principles of Hooke’s Law and the concept of elastic moduli, engineers and designers are better equipped to accurately predict and prevent potential cracks arising from excessive deformation.
Thermal movement emerged as a fundamental consideration, highlighting the profound impact of temperature fluctuations on building materials. The study emphasized the necessity of accommodating these temperature-induced dimensional changes through expansion joints, flexible connections, and appropriate material selection. By effectively managing thermal movement, structures can withstand the cyclic stresses and strains that often result in cracks.
Shrinkage, another crucial factor, was explored in detail, revealing its role as a significant contributor to building cracks. The study emphasized the importance of controlling mix design, curing techniques, and moisture content to mitigate shrinkage-related cracks. Employing innovative solutions such as shrinkage-compensating admixtures holds promise in enhancing the resilience of construction materials.
As the study merged these factors, the understanding of how they interact synergistically to cause complex crack patterns was evident. Integrated design approaches, considering joint spacing, flexible materials, and reinforcement detailing, emerged as effective strategies to manage the combined effects of elastic deformation, thermal movement, and shrinkage.
In the pursuit of constructing durable, safe, and aesthetically pleasing structures, it is imperative for architects, engineers, and construction professionals to internalize the insights from this study. By leveraging the knowledge gained about elastic deformation, thermal movement, and shrinkage, practitioners can adopt informed design principles, select appropriate materials, and implement effective construction techniques to mitigate the risks associated with building cracks on walls.
Nonetheless, it is essential to recognize that while this study has significantly contributed to the understanding of building cracks, its scope has limitations. The complexities of real-world scenarios, the diversity of materials and construction practices, and the evolving nature of technology warrant continuous research and adaptation. Therefore, future studies can further build upon these findings, refining strategies, and expanding our understanding of these critical factors in building construction.
Recommendation
Based on the comprehensive study of building cracks on walls, focusing on elastic deformation, thermal movement, and shrinkage, the following recommendations are proposed to guide future design, construction, and maintenance practices:
Incorporate detailed structural analysis that considers elastic deformation effects under various load scenarios.
- Utilize advanced structural engineering software for accurate prediction of stress and strain distribution to prevent excessive deformation.
- Prioritize materials with low coefficients of thermal expansion to minimize temperature-induced stresses.
- Conduct thorough material testing to assess shrinkage characteristics and inform mix design adjustments for reduced cracking potential.
- Integrate well-designed expansion joints strategically in structures to accommodate thermal movement and prevent uncontrolled cracking.
- Incorporate flexible connections in critical areas to absorb deformation caused by elastic responses.
References
- Kearsley, E. P., Forde, M. C., & Price, A. D. F. (2010). The significance of thermal movement in building design. Structural Survey, 28(3), 209-217.
- ACI Committee 207. (2019). Mass Concrete (ACI 207.1R-19). American Concrete Institute.
- Neville, A. M. (2004). Properties of concrete (4th ed.). Pearson Education.
- Dutta, S., Samanta, S., & Saha, D. (2013). Analysis of expansion joints in pipelines and design considerations. International Journal of Engineering Research & Technology, 2(10), 1856-1864.
- Popovics, S., Balázs, G. L., & Klebercz, O. (2003). Load analysis and control in reinforced concrete design. Periodica Polytechnica Civil Engineering, 47(2), 181-192.
- Mehta, P. K., Monteiro, P. J., & Concrete, A. C. I. (2006). Concrete: microstructure, properties, and materials. McGraw-Hill.
- Trahair, N. S., Bradford, M. A., & Nethercot, D. A. (1992). The behaviour and design of steel structures to EC3. E & FN Spon.
- Hart, C. A. (1982). Mechanics of Wood and Wood Composites. Van Nostrand Reinhold.
- Salamone, S., Santarsiero, G., Fatiguso, F., & Polito, D. (2018). A numerical method for the static analysis of beams and columns. Structural Concrete, 19(2), 487-495.
- Hobbs, B. J., Williams, M. S., & LaFave, J. M. (2019). Assessment of building load path continuity to prevent potential sudden and progressive collapse. Engineering Structures, 182, 16-30.
- Wardhana, K., Brinkgreve, R. B. J., & Potts, D. M. (2017). Settlement induced cracking in brick masonry buildings. Engineering Structures, 131, 300-314.
- ACI Committee 318. (2019). Building Code Requirements for Structural Concrete (ACI 318-19). American Concrete Institute.
