From July 1, updated requirements for the quality of asphalt concrete mixtures come into force in Kazakhstan.
"Changes have been made to the national standard ST RK 1225-2019 'Road, airfield asphalt concrete mixtures and asphalt concrete' and are aimed at improving the reliability of road infrastructure and reducing operational risks," the press service of the Ministry of Transport reported.
The developer of the updated standard was the Kazakhstan Road Research Institute (KazdorNII). Scientists and specialists from the institute conducted tests and scientific research taking into account actual road operating conditions and international requirements.
"The decision is based on the results of laboratory studies, which showed that during the repeated moulding of asphalt concrete samples, intensive crushing of crushed stone occurs - up to 18% during standard compaction. This affects the structure of the material and distorts test results, making the water saturation indicator irrelevant," noted KazdorNII.
The update of the standard is expected to lead to an objective quality control system and increase the efficiency of road construction. For contractors and manufacturers, this means:
- introduction of modern control methods adapted to actual conditions;
- minimisation of risks of incorrect tests;
- clear and predictable technical requirements;
- cost reduction by increasing the reliability of the road surface.
Additional changes include:
- revision of the temperature regime for laying the mixture;
- clarification of the compaction coefficient;
- specification of requirements for the adhesion of stone material to bitumen;
- expansion of the scope of application of mixtures to airfields, city streets, and industrial facilities.
"This approach allows us to ensure not only compliance with international requirements, but also to take into account the specific climatic and operational conditions of Kazakhstan in real time," the conclusion states.
Let us recall that earlier, in the Pavlodar and Turkestan regions, heaving of concrete sections of highways was recorded. This caused a wave of criticism on social media, but the company 'KazAvtoZhol' explained that the reason was the heat, not poor-quality construction.