Prestressed Concrete Sleepers: Failure Investigation Case Study

2020 ◽  
pp. 167-170
Author(s):  
D. Yurlov ◽  
A. Shishkin ◽  
S. Zhutovsky
Keyword(s):  
Prestressed Concrete ◽  
Failure Investigation

Gas pockets in a wastewater rising main: a case study

2012 ◽  
Vol 66 (10) ◽  
pp. 2265-2274 ◽  
Author(s):  
Oscar Pozos-Estrada ◽  
Oscar A. Fuentes-Mariles ◽  
Adrian Pozos-Estrada
Keyword(s):  
Prestressed Concrete ◽  
Contributory Factor ◽  
In Situ Observation ◽  
Flow Conditions ◽  
Transient Event ◽  
Power Failure ◽  
Fluid Transients ◽  
Prestressed Concrete Cylinder Pipe

This paper presents a case study of an existing wastewater rising main (WWRM) in which an extreme transient event produced by simultaneous power failure of the pumps caused the rupture of a 1.2 m (48 in) prestressed concrete cylinder pipe (PCCP), causing an important leakage of sewage. The event and the methodology followed in order to validate the diagnostics of the failure are described. The detail study included in situ observation of the system, experimental investigation in a setup, hydraulic analysis, as well as details of the structural strength of the WWRM. After the extensive investigation and several simulations of fluid transients for different scenarios and flow conditions, it was found that stationary small gas pockets accumulated at high points of the WWRM were identified as the principal contributory factor of the failure. This case study serves as clear warning of the consequences of operating a WWRM with gas pockets at its high points.

Carbon Footprint Analysis of Fibre Reinforced Polymer (FRP) Incorporated Pedestrian Bridges: A Case Study

2012 ◽  
Vol 517 ◽  
pp. 724-729
Author(s):  
Jian Guo Dai ◽  
Tamon Ueda
Keyword(s):  
Construction Industry ◽  
Carbon Footprint ◽  
Prestressed Concrete ◽  
Environmental Friendliness ◽  
Pedestrian Bridge ◽  
Reinforced Polymer ◽  
Pedestrian Bridges ◽  
Fibre Reinforced Polymer ◽  
Footprint Analysis

This paper presents a case study on the carbon footprint of a fibre reinforced polymer (FRP)-incorporated pedestrian bridge in comparison with a conventional prestressed concrete (PC) one. The CO2 emission is used as an index and calculated for both the material manufacturing and the construction processes. It is shown that using an FRP-incorporated pedestrian bridge to replace a conventional prestressed concrete (PC) bridge may reduce the CO2 emission by 18% and 70%, respectively, during the material manufacturing and construction periods, leading to a total reduction by about 26%. Such reduction is expected to be more significant if the life-cycle CO2 emission is accounted for, since the former type of bridge is free of corrosion and almost maintenance-free. Therefore, FRP-incorporated bridges may become a more competitive alternative to conventional reinforced concrete (RC) or PC ones with the increasing attention paid on the sustainability and environmental friendliness of construction industry by our society.

scholarly journals Exploring life cycle-based sustainability indicators for building structural frames in concrete

2013 ◽  
Vol 6 (5) ◽  
pp. 832-843 ◽  
Author(s):  
F. R. M. Oliveira ◽  
M. G. Silva ◽  
V. Gomes
Keyword(s):  
Life Cycle ◽  
Prestressed Concrete ◽  
Residential Buildings ◽  
Environmental Indicators ◽  
Functional Equivalence ◽  
Concrete Frames ◽  
Study Approach ◽  
Life Cycle Perspective ◽  
Service Life Estimation

This paper aims at advancing on the validation of indicators of building concrete frames' sustainability from an integrated, life cycle perspective. A case study approach investigates (i) feasibility of comparing sustainability performance of different flooring systems; and (ii) similarity between environmental indicators trends for a typical flooring system and corresponding whole superstructure. Three residential buildings are analyzed, using either prestressed concrete flat (PCF) slabs or reinforced concrete waffle (RCW) slabs and flat beams exposed to a marine environment. SimaPro 7.3 supports calculation of the environmental indicators. Service life estimation is used to ensure functional equivalence and to form a basis for life cycle costing. PCF slabs showed best functional/technical and economic results but were outperformed by RCW slabs' environmental results. Most environmental indicators showed the same trend for both typical floor and whole superstructure.

scholarly journals Investigation of repeated economiser tube failures of a 135 tph cold cyclone CFB boiler – a case study

2021 ◽  
Vol 71 (5&6) ◽  
pp. 73
Author(s):  
Chittatosh Bhattacharya
Keyword(s):  
Failure Analysis ◽  
Coal Ash ◽  
Fluidised Bed ◽  
Cfb Boiler ◽  
Failure Investigation ◽  
Short Span ◽  
Operational Practices ◽  
External Corrosion ◽  
Circulating Fluidised Bed

There were quick and successive failures of economiser tubes in a four years old cold cyclone circulating fluidised bed 135 tph boiler in a short span of three months. Advance inspection and failure analysis, change in operational practices were used to get the boiler running at full load at the earliest possible time. This paper presents details of the process of inspection, maintenance, operation and failure investigation carried out for the economiser tubes of the boiler. The failure of the economiser tubes was due to external corrosion of the tubes furnace fire side due to presence of sulphur in coal, accompanied by localised erosion by high levels of alpha-quartz in coal ash.

Smokeless flare tips failure investigation: case study

2019 ◽  
Vol 37 (1) ◽  
pp. 11-15
Author(s):  
Anaam H. Al-Shaikhali ◽  
Hameed H. Al-Badairy ◽  
Abdelmounam M. El-Sherik
Keyword(s):  
Failure Investigation
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