Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Cementitious Liners in Reinforced Concrete Pipes
This thesis investigates the performance of damaged reinforced concrete pipes with a focus on developing design approaches to examine the required thickness of cementitious liners to restore strength to resist earth and vehicle loads. Design seeks to prevent the development of additional cracking within the damaged concrete pipe and cracking within the liner material due to circumferential bending moments at the pipe crown, to limit both stormwater contact with reinforcing and continued pipe corrosion. Several different deteriorated pipe conditions are considered: flexural cracks, losses of concrete cover and tensile reinforcement, as well as an extreme condition where the host pipe is assumed to have lost all capacity to resist bending moments. Sample calculations quantify how the required cementitious liner thickness increases as the extent of deterioration within the concrete pipe increases. The project involves both theoretical and experimental work. An experimental program was undertaken to examine the mechanics of cracked reinforced concrete pipes. The experimental work presented in this thesis serves as a first step in forming an understanding between the developed cracks and bending moments within reinforced concrete pipes (where bending moments influence both reinforced concrete pipe design as well as cementitious liner design). Reinforced concrete pipes were instrumented with optical fibres and then buried in graded granular fill. Strain measurements around the inner and outer surfaces were taken as burial depth was increased from 0.6m to 1.2m. The measured strains showed the continuous evolution of crack widths as curvatures associated with bending moments increased with burial. Measurements indicated that a 60cm increase in soil cover (approximately 1/10th of the standard burial depth for the Class 4 pipes used for experimentation) resulted in increases of crack width between 0.025mm and 0.06mm (approximately 1/10th and 1/5th of the AASHTO allowable crack limit, respectively). The calculated crack ...
Cementitious Liners in Reinforced Concrete Pipes
This thesis investigates the performance of damaged reinforced concrete pipes with a focus on developing design approaches to examine the required thickness of cementitious liners to restore strength to resist earth and vehicle loads. Design seeks to prevent the development of additional cracking within the damaged concrete pipe and cracking within the liner material due to circumferential bending moments at the pipe crown, to limit both stormwater contact with reinforcing and continued pipe corrosion. Several different deteriorated pipe conditions are considered: flexural cracks, losses of concrete cover and tensile reinforcement, as well as an extreme condition where the host pipe is assumed to have lost all capacity to resist bending moments. Sample calculations quantify how the required cementitious liner thickness increases as the extent of deterioration within the concrete pipe increases. The project involves both theoretical and experimental work. An experimental program was undertaken to examine the mechanics of cracked reinforced concrete pipes. The experimental work presented in this thesis serves as a first step in forming an understanding between the developed cracks and bending moments within reinforced concrete pipes (where bending moments influence both reinforced concrete pipe design as well as cementitious liner design). Reinforced concrete pipes were instrumented with optical fibres and then buried in graded granular fill. Strain measurements around the inner and outer surfaces were taken as burial depth was increased from 0.6m to 1.2m. The measured strains showed the continuous evolution of crack widths as curvatures associated with bending moments increased with burial. Measurements indicated that a 60cm increase in soil cover (approximately 1/10th of the standard burial depth for the Class 4 pipes used for experimentation) resulted in increases of crack width between 0.025mm and 0.06mm (approximately 1/10th and 1/5th of the AASHTO allowable crack limit, respectively). The calculated crack ...
Cementitious Liners in Reinforced Concrete Pipes
Jackson, Russell (Autor:in) / Civil Engineering / Moore, Ian / Genikomsou, Aikaterini
12.02.2025
Hochschulschrift
Elektronische Ressource
Englisch
Reinforced , Concrete , Pipes , Liners , Rehabilitation
The Role of Cementitious Liners on the Structural Preservation of Overburdened Buried Concrete Pipes
| Springer Verlag | 2022