| Date | Development information | More info |
| 1968 | Development of Mk I prototype | more information... |
| 1972 | Development of Mk II HVS | more information... |
| 1977 | Development of Mk III HVS | more information... |
| 1978 | Initiation of HVS programme in South Africa | |
| 1980 | Development of Multi-Depth Deflectometer (MDD) | more information... |
| 1980 | First draft TRH4 guideline on structural design complete | |
| 1981 | HVS testing of a slag material | |
| 1982 | First draft of South African Mechanistic Design Method | pdf doc. 834 kb. size |
| 1982 | HVS testing on taxiway of Johannesburg International Airport | |
| 1982 | Criteria for the sealing of cracked roads determined for PMS from HVS testing | |
| 1983 | Testing of bitumen-rubber seals over active cracks at Hornsnek | |
| 1985 | Second draft of TRH4 guideline for structural design completed | |
| 1985 | Development of Crack Activity Meter | more information... |
| 1986 | Testing on cement treated bases initiated - leading to new failure criteria and design methods | pdf doc. 236 kb. size |
| 1991 | Initial work on granular emulsion mixes (GEMS) completed | |
| 1991 | Initial work on large agregate mixes for bases (LAMBS) completed | pdf doc. 224 kb. size |
| 1992 | First Structural design curves for ETB's from HVS testing | |
| 1993 | Final evaluation of the performace of GEMS under HVS testing | |
| 1993 | Development of a temperature control chamber for the HVS | more information... |
| 1994 | Development of a new data acquisition (DAQ) system for the HVS | more information... |
| 1994 | HVS evaluation of the Caltrans trial sections in South Africa | |
| 1994 | Purchase of two HVS Mk III units by Caltrans for testing in California | |
| 1995 | HVS testing of the upgrading of gravel roads | |
| 1995 | New design curves for "superlight" pavements from HVS testing | |
| 1995 | Porous asphalt evaluated under the HVS | |
| 1996 | HVS Mk IV unit delivered to Cold Regions Research and Engineering Laboratory (CRREL) of the US Corp of Army Engineers | |
| 1996 | Update of the South African Mechanistic Design Method | |
| 1996 | Update of the TRH4 structural design guide from HVS testing | |
| 1996 | Development of a new strategy for the GDPTRW HVS in South Africa | pdf doc. 64 kb. size |
| 1996 | Development of the 3D stress sensor | more information... |
| 1996 | Development of the Laser Profilometer for the HVS | more information... |
| 1997 | HVS MK IV unit delivered to Road Research Laboratories in Finland and Sweden (VTT and VTI) | |
| 1997 | Development of a new dynamic test method using the K-mould | |
| 1997 | Modelling of permanent deformation in lower pavement layers using historic HVS data | pdf doc. 913 kb. size |
| 1997 | Modelling of in-depth deflection bowls | |
| 1998 | Comparison of base materials constructed using Labour Intensive Constuction (LIC) techniques | pdf doc. 178 kb. size |
| 1998 | Design and construction of a new HVS-A for airport testing, called "Bigfoot" | image... |
| 1998 | Design and construction of new CSIR Built Environment HVS intended for simulating dynamic loading | image... |
| 1999 | Testing of Labour Intensive Constructed Waterbound Macadam base layer near Louis Trichardt | CR99065 |
| 2000 | Initial work on foam- and emulsion treated gravel near Vereeniging | pdf doc. 2.1 Mb. size |
| 2001 | Interim guidelines. The design and use of foamed bitumen treated materials | |
| 2002 | Aquisition of new Mk IV+ dynamic loading HVS by GDPTRW | |
| 2002 | Comparative testing of GDPTRW HVS Mk III and HVS Mk IV+ at Cullinan test site | Current testing |
During
the 50's and 60's it became apparent that the performance of a road
could not be predicted solely from laboratory experiments. Accordingly
there was significant worldwide interest in the development of methods
for accelerated testing of full-scale road pavements.
The first attempts
involved the construction of special test sections that were then trafficked
by a special fleet of trucks. Tests of this nature include the AASHTO
road tests and a number of road trials in Britain. The CSIR also embarked
on such a testing programme, but it was found to be both time consuming
and expensive. This lead to the concept of a testing device that could
accelerate the damage caused by trafficking.
Initial testing facilities took the form of either circular or linear test tracks. However these facilities were fixed and therefore the pavements had to be especially constructed under the machine. This proved particularly difficult in the case of circular tracks. The then National Institute of Transport and Road Research of the CSIR (NITRR). investigated the establishment of a linear test track facility, and in 1966 a fixed testing rig, built from Bailey Bridge sections, had been constructed.
This led to the concept of the prototype HVS. This prototype was commissioned
in October 1970. The machine went into immediate operation and by 1972
the data collected was so promising that it was decided to commission
3 more HVS's, incorporating a large number of design improvements based
on the experience gained with the prototype. These machines where commissioned
between April, 1976 and December, 1978. Initially, operation of the HVS
fleet was restricted to the general area around Pretoria, both to facilitate
the training of staff and the development of such ancillaries as the instrumentation
and data monitoring and acquisition systems. By 1980 the operations of
the fleet were extended throughout South Africa. Since 1978, the fleet
of 4 HVS's (prototype Mark IV & Mark III's) have been used to test
more than 400 test sections including trial sections and in-service pavements.
In this process an information and results database of more than 4 gigabytes
was developed. This work has had a major impact on road engineering in
South Africa, particularly in the areas of materials design, structural
design and rehabilitation design.