Constraining Causes Of Structural Failure Using Electrical Resistivty Tomography (ERT): A Case Study Of Lagos, Southwestern, Nigeria

2010 ◽  
Author(s):  
Elijah A. Ayolabi ◽  
Adetayo F. Folorunso ◽  
Moroof O. Oloruntola
Keyword(s):  
Structural Failure ◽  
Southwestern Nigeria

A probabilistic approach for design and certification of self-healing advanced composite structures

2011 ◽  
Vol 225 (4) ◽  
pp. 435-449 ◽  
Author(s):  
H R Williams ◽  
R S Trask ◽  
I P Bond
Keyword(s):  
Composite Structures ◽  
High Performance ◽  
Probabilistic Approach ◽  
Healing Time ◽  
Self Healing ◽  
Structural Failure ◽  
Healing System ◽  
Order Of Magnitude ◽  
Damage Tolerant

Design and certification of novel self-healing aerospace structures was explored by reviewing the suitability of conventional deterministic certification approaches. A sandwich structure with a vascular network self-healing system was used as a case study. A novel probabilistic approach using a Monte Carlo method to generate an overall probability of structural failure yields notable new insights into design of self-healing systems, including a drive for a faster healing time of less than two flight hours. In the case study considered, a mature self-healing system could be expected to reduce the probability of structural failure (compared to a conventional damage-tolerant construction) by almost an order of magnitude. In a risk-based framework this could be traded against simplified maintenance activity (to save cost) and/or increased allowable stress (to allow a lighter structure). The first estimate of the increase in design allowable stresses permitted by a self-healing system is around 8 per cent, with a self-healing system much lighter than previously envisaged. It is thought these methods and conclusions could have wider application to self-healing and conventional high-performance composite structures.

Gravel Mining and Supply for Construction – A Case Study of Southwestern Nigeria

2013 ◽  
Vol 824 ◽  
pp. 44-50
Author(s):  
B.I.O. Dahunsi ◽  
N.A. Sulymon
Keyword(s):  
Research Data ◽  
The State ◽  
Truck Drivers ◽  
Southwestern Nigeria ◽  
Factors Affecting ◽  
Gravel Mining ◽  
Prohibitive Cost ◽  
The Cost ◽  
Structured Questionnaire

This paper discusses the perception of gravel suppliers in the six states situated in South-western Nigeria. It reported findings from a research on gravel supply studies in the study area. Major gravel pits, together with their perceived technical characteristics in the states were identified through a structured questionnaire designed to solicit response from truck drivers and association of gravel suppliers. Based on this, factors affecting gravel supply and usage were measured by random variables devised for the purpose. The observed outcomes of the variables from the survey carried out constituted the research data. The collated data was analyzed based on quantitative method through the use of simple percentage method of data analysis. The paper posits that geological location of Lagos state is responsible for the absence of any gravel pit in the state, hence the prohibitive cost of gravel in the state when compared to other states in the zone. In all the states, more than 99% of gravel suppliers attribute transport as a major factor affecting the cost of gravels. The technical characteristics of gravels from South-western Nigeria are also perceived to be good in construction, though these assertions need to be empirically proved.

scholarly journals Diagnostics of the structural failure of sports hall external wall layers

2019 ◽  
Vol 284 ◽  
pp. 02005
Author(s):  
Leopold Kruszka ◽  
Pawel Muzolf
Keyword(s):  
Technical Condition ◽  
The Other ◽  
Diagnostic Process ◽  
Construction Technology ◽  
Structural Failure ◽  
External Wall ◽  
Aerated Concrete ◽  
Structural Failures ◽  
Construction Defects

The paper presents the diagnostics of the technical condition of the external layers of the sports hall walls. Structural failures related to construction defects themselves constitute a relatively small percentage (4.1% in 2017, 5.05% in 2014-2017 [1]), although the main reason for them is the lack of maintaining technological rigors (76.9% in 2017, 68.4% in 2014-2017 [1]). The presented and described case study of the technical condition of the newly built sports hall does not refer to structural failure, but to the reduction of the risk of that failure as a result of non-compliance with construction technology, in particular, in relation to the external walls. Contrary to the design, the walls of the sports hall were made of aerated concrete. According to the declaration of a designer, the contractor neither consulted the changes with the designer nor gain the acceptance of the designer for using aerated concrete instead of the primary proposed and designed brick structure. In addition, aerated concrete curtain walls with a height of about 4.5 m were made without any wall connectors. This resulted in a risk of a structure failure involving the collapse of its curtain walls. The technological requirements for the repairing of the elements of supporting walls as well as the diagnostic process of the other damaged finishing cladding of external walls are also provided in this paper.

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