Create smooth high-quality surfacing and roads with National Asphalt's Hot Mix Asphalt (HMA) product, often referred to as tar. 100% Recyclable with quality accredited aggregate and bitumen combination, our product is easy to handle and apply, cooling down quickly - offering less traffic disruption. Aside from our numerous commercial fixed plants across South Africa and Botswana, we also offer a mobile plant option to our clients. Mobility is our speciality offering plant production capabilities from 10t/hr to 140t/hr allowing us to tailor solutions for projects of all shapes and sizes.
FEATURES AND BENEFITS OF HOT MIX ASPHALT
- Deliver to you or set-up mobile plant
- Lower life cycle cost than concrete
- Smooth and quiet roads - reduce fuel consumption and lower vehicle maintenance costs
- 100% recyclable - old asphalt can be re-used as aggregate or stockpiled
- Cools down within hours - less disruption
- Pavement strength and flexibility - lasting with minimum water ingress
Stone matrix asphalt (SMA) is a gap-graded HMA (Figure 1) that is designed to maximize deformation (rutting) resistance and durability by using a structural basis of stone-on-stone contact.
Bitumen Treated Base or the base course is the lower asphalt course/layers, below the surface and any levelling course. The base course provides the strength of the pavement and typically has an aggregate nominal particle size of 20mm.
The wearing course is the upper layer in roadway or runway. The main function of wearing course is to provide impervious layers so that entry of water to the base course can be prevented. Moreover the entire traffic load is safely distributed over the base course.
Polymer modified asphalt
PMB consists of bitumen blended with a synthetic polymer. PMBs are used to enhance the performance of binders on heavily trafficked or distressed pavement surfaces, often in adverse climatic conditions. Asphalt made with modified binders are more resistant to fatigue, thermal cracking, rutting, stripping, and temperature susceptibility than neat binders. Polymer modified binders tend to exhibit increased viscosity and elastic recovery.
Rubber modified binder has been shown to increase the fatigue resistance and durability of asphalt. Adding rubber crumb to the neat binder retards aging and oxidation of the resulting binder, which increases pavement life by lessening brittleness and cracking. Rubber modified asphalt binders can be used in open-graded asphalt mixtures, which have reduced hydroplaning, vehicle spray and reduced pavement noise.
EME is based on French technology Enrobé à Module Élevé developed in the 1980’s where low penetration – very hard – bitumen binders are used to produce very stiff asphalt layers. This high-performance and high-quality road construction material intended for use in heavy duty pavements due to its exceedingly high modulus. It is particularly suitable for pavements carrying large volumes of heavy vehicles.
Warm mix asphalt is typically produced at 20-40˚ C lower than hot mix asphalt. The benefits of WMA are that it improves asphalt compaction. Allows asphalt mix to be hauled longer distances. Improves working conditions by reducing exposure to fuel emissions, fumes, and odours.
- Hot mix asphalt containing up to 40% of reclaimed asphalt
- It saves money
- It is better for the environment
- It reduces other waste in landfills
- It conserves other natural resources
- The durability and longevity of recycled asphalt materials increases
- It has many uses beyond road paving
Ultra Thin Friction Course/Open Grade asphalt – are types of asphalt mixes that contain only a small portion of fine aggregate, creating a pavement with a relatively large percentage of air voids. UTFC has the benefits of removing pavement surface water, absorbing traffic noise and increasing friction resistance.
Fuel resistant asphalt
This binder is applied in zones where there is frequent contact with hydrocarbons, airport zones, bus lanes, fleet parking zones or prolonged parking zones, highway toll areas, and service stations and garages.
Fuel-resistant bitumen has the following advantages over conventional binders:
- Greater resistance to hydrocarbons than conventional binders
- Less susceptibility to temperature and aging
- High resistance to high service temperatures