Concrete Diagnostics and the Assessment of Existing Structures
01.
2010 Soccer World Cup Moses Mabhida Stadium Complex, Durban
(Structural Condition Assessment for the Entire Stadium complex, followed by Remedial Design for the Failed Movement Joints)
DPA Specialist Consulting Engineers were appointed to carry out a comprehensive structural condition assessment and high-level remedial design concept, and method statement, for the failed movement joints at the Moses Mabhida Stadium in Durban. To facilitate the remedies necessary for the stadium, it was essential that a detailed structural condition assessment be undertaken to the expansion joint components, allowing for the development of remedial designs and quantification of the severity and extent of the issue.
DPA’s services included the use of ground-penetrating radar (GPR) and electro-magnetic cover-meter surveying techniques to locate the reinforcing steel in the concrete nibs and slab end. DPA’s scope was extended to determine which joints were or were not compliant in terms of meeting the criteria of relevant OHS ACT and Construction Regulation Code and the design of appropriate structural augmentation and bearings. During the Construction Monitoring Phase, DPA provided full-time construction monitoring of the remedial Works to ensure that compliance with the design and specifications were met and a review of the Contractors temporary propping arrangements and safety measures.
02.
2010 Soccer World Cup Moses Mabhida Stadium Complex, Durban
(Complex Wide Structural Condition Assessment, including a Comprehensive Reinforced Concrete Durability Diagnostic Survey)
eThekwini Municipality awarded the Tender to DPA Specialist Consulting Engineers to carry out a comprehensive condition assessment and risk management profile for the civil structures comprising the Moses Mabhida Stadium complex.
Due to the apparent number of deficiencies which had arisen in a surprisingly short period of time since the construction of this world class facility and to facilitate the remedies necessary for the stadium, it was recommended that a detailed structural and durability condition assessment be undertaken to the civils components. This activity was carried out by DPA’s engineers and NACE certified Coating Inspectors.
This assessment included remedial options and broad-based budgets to facilitate decision making and allow the stadium to be brought back into a suitably functioning and durable condition in line with its status as a world class venue.
03.
Mondi Kraft Paper Mill, Richards Bay, KZN
(Civil Refurbishment of Chemical Plant Portal Frame Structure)
The Chemical Plant was condemned by other structural engineers, resulting in DPA’s appointment to implement a remedial strategy which included Cathodic Protection and corrosion inhibitor technology.
Mondi Richards Bay initiated a project to upgrade the Chemical Plant, which included a requirement to ensure a further 20 years safe operating life for the civil structures of the 621 and 651 Cell Rooms within the Chemical Plant. These structures were erected approximately 35 years ago and have, to varying degrees, been exposed to aggressive substances which have caused severe damage to certain structural elements.
DPA Specialist Consulting Engineers were appointed to perform a condition assessment of the civil structures and to design a refurbishment strategy that will guarantee the required 20 years safe operational life while causing minimum disruption to plant operations. DPA was appointed to carry out the QA monitoring using our engineering team and one full time NACE Certified Coating Inspector.
04.
Elizabeth Bay Reservoir, Namibia
(Structural Restoration)
A coastal diamond recovery operation in Namibia required DPA’s input in saving a severely corroded & structurally unstable salt water reservoir, which was critical to the recovery operations in the plant. DPA undertook some forensic diagnostic procedures to determine the current condition and loss of structural performance as a result of severe Chloride induced corrosion. The structure had been considered at risk of structural collapse due the severely corroded rebar within the concrete walls.
A short-term remedial design was carried out to allow continued operation of the facility during the reservoir remedial operations. The structural capacity was augmented by the installation of a specially designed post-tensioned cabling system.
05.
Biscuit Factory, Westmead, Kwazulu-Natal
(External Structural Refurbishment)
DPA Specialist Consulting Engineers were appointed to carry out a condition assessment and the design of structural remedial works to the external fabric of a biscuit production factory located in Westmead, Kwazulu-Natal. The composite brick and steel-frame structure was displaying significant cracking in the brick-cladding accompanied by spalling of reinforced concrete elements and general deterioration of the external finishes.
The remedial project concluded in a significant façade upgrade with DPA continuing to be involved with the Client as a result of the success of this project, in their other national facilities.
06.
Biscuit Factory, Westmead, Kwazulu-Natal
(Concrete Diagnostics)
As a result of concerns that have arisen from spalling concrete and obvious visual defects evident on the concrete portal frame elements at a biscuit production factory located in Westmead, Kwazulu-Natal, DPA Specialist Consulting Engineers were appointed to undertake a localised concrete diagnostic survey and report on the findings.
07.
Paper Mill, Gauteng
(Concrete Diagnostics)
DPA have worked for a paper group at their paper processing facility, located in Gauteng, for many years, handling their corrosion and structural issues. A number of concrete diagnostic surveys resulted in plant-wide preventative maintenance upgrades and restoration projects.
08.
Synthetic Fuels Plant, Secunda
(Concrete Diagnostics)
During the late 90’s and into 2001, DPA were involved in considering high-level remedials to the four Process Water Cooling Towers at a synthetic fuel facility in Secunda, Mpumalanga. A localised condition assessment, together with limited concrete diagnostics proceeded a high-level rim repair to one of the Cooling Towers.
Access was gained by means of an Alimac mechanical hoist with the installation and load carrying review with respect to the structure having been carried out by DPA. During the course of the first remedial operation, significant further data regarding the levels and type of contamination were accumulated and a comprehensive condition assessment of the contaminants and high-level structural elements was undertaken
09.
Synthetic Fuels Plant Concrete Chimney Stack, Secunda
(Condition Assessment – Concrete)
The 305m high concrete windshield of one of the chimney stacks at a synthetic fuels plant located in Secunda, Mpumalanga, required the services of DPA after concerns had been raised with respect to the condition of the reinforced concrete and the upper roof slab integrity.
DPA undertook the investigation and assessed the general condition of the external surface of the reinforced concrete windshield with respect to corrosion whilst the appointed Contractor implemented the remedial design. DPA monitored the remedial works in progress.
10.
Synthetic Fuels Process Cooling Tower, Secunda
(Concrete Sampling Investigation & Condition Assessment)
DPA Specialist Consulting Engineers were appointed to remove 18 cores from a Process Cooling Tower at a synthetic fuels plant located in Secunda, Mpumalanga, and to analyse these for contaminants and to provide the Client with an opinion following a review of these results.
The limited diagnostic investigation & report was completed in 2016.
