Chris Rust

CSIR 3rd Biennial Conference 2010. Science Real and Relevant, CSIR International Convention Centre, Pertoria 30 August – 01 September 2010, South Africa In 2006, the South African Institution of Civil Engineering (SAICE), utilising desktop research documentation prepared for this specific purpose by the CSIR, released the first ever “report card” of the state of engineering infrastructure in South Africa. This highlighted “the observations of the professionals responsible for the planning, construction, operation and maintenance of our nation’s life-support system”. It graded infrastructure (water, sanitation, solid waste, roads, airports, ports, rail, electricity and hospitals and clinics) on a scale from A+ through E-. Overall, it gave the nation’s infrastructure a D+ grade. The importance of infrastructure for social and economic development is underestimated and consequently its maintenance is often neglected. The purpose of the report card was to draw the attention of governmen...

The purpose of the “national infrastructure report cards” of the condition of engineering infrastructure in South Africa has been to draw the attention of government, and of the South African public at large to the importance of maintenance, and to factors underlying the state of repair of infrastructure. The success of these report cards, published in 2006 and 2011, has been such that a new report card is currently being prepared. Whereas completion of this, the third report card, will not take place until around mid-year, the objective of this paper is to briefly describe the background to and purpose of infrastructure report cards and the process by which the South African report cards are compiled, to discuss key findings of the previous report cards, and to describe the third report card’s preliminary findings for the water sector.

The Council for Scientific and Industrial Research (CSIR) has conducted several research studies associated with understanding the behavioural characteristics and performance of new innovative pavement structures stabilised with Nano-Organosilane Modified Emulsions (NMEs). These pavement structures could play a significant role for local road agencies in South Africa as they may be utilised as a cost-effective alternative to conventional road designs, thus reducing economic constraints and road maintenance backlogs. Since 2017, a series of Heavy Vehicle Simulator (HVS) tests have been conducted on several road sections across South Africa, most notably on Gauteng Provincial Road D1884 in Meyerton and on Gauteng Provincial Road K46 near Diepsloot. Both these road sections consist of bespoke designs that incorporate NME base and subbase layers. The aim of this paper is to present performance results as obtained from these HVS tests. It is anticipated that these results will provide a good indication of the potential benefits and risks of using NME materials as opposed to using costly imported crushed aggregates, which are typically required for conventional South African road designs. These HVS results in conjunction with previously published laboratory data conclude that NME pavement layers exhibit exceptional performance, thus prompting the need for quicker standardisation and implementation of NMEs across South Africa.

In 2006 the South African Institution of Civil Engineering (SAICE) released the first ever ‘report card’ of the state of engineering infrastructure in South Africa. This report highlighted ‘the observations of the professionals responsible for the planning, construction, operation and maintenance of our nation’s life-support system’. It graded infrastructure on a scale from A+ to E−. Overall, it gave South Africa’s infrastructure a D+ grade. The purpose of the report card was to draw the attention of government, and of the public at large, to the importance of maintenance, and to factors underlying the state of repair of infrastructure – factors such as skills and finance, for example. The report card was a great success, and received media coverage exceeding the Institution’s highest expectations. The SAICE 2011 Infrastructure Report Card was launched in April 2011. It covers ten sectors, further divided into 27 subsectors. These have been graded and the trend since 2006 is indicat...

Crack reflection on roads with cemented layers is a significant problem worldwide and can lead to premature failure. Innovative road materials such as bitumen-rubbers possess the potential to successfully retard crack reflection, thereby minimizing damage to roads from water ingress. The research work conducted on bitumen-rubbers in conjunction with the knowledge generated on the retardation of crack reflection has led to several developments and innovations for the road industry. One such innovation is the development of the Crack Activity Meter (CAM), a device capable of measuring horizontal and vertical crack movements simultaneously. The CAM has been successfully used in conjunction with the Heavy Vehicle Simulator (HVS) during several accelerated pavement tests of road sections containing bitumen-rubber materials. Results from various laboratory investigations in conjunction with these field tests spans over decades of research into aspects such as crack movement monitoring, fa...

Upgrading, maintenance and rehabilitation of road infrastructure is expensive, especially in view of the growing scarcity and cost of suitable road building materials. In areas with high mica content and secondary minerals such as smectite in the natural materials, stabilisation with cement is not viable. The Council for Industrial and Scientific Research of South Africa has embarked on a research programme to evaluate the performance of substandard materials improved with anionic nano-silane modified bitumen emulsions for use in base and subbase layers. This work comprises laboratory testing as well as Accelerated Pavement Testing using the Heavy Vehicle Simulator (HVS). The results of a full-scale HVS test on a light pavement as well as initial analysis on a medium traffic road are discussed. It has been shown that stabilisation of available substandard materials using an anionic nano-silane modified bitumen emulsion compared with the standard approach of importing high quality crushed aggregate can lead to savings as high as 40%–50% for equivalent performance. In addition, there was also a significant reduction in construction effort and time.