Table of Contents
Preparation of the existing base course layer
Bitumen road construction entails a number of phases, including base course preparation, bituminous coat application, bituminous mix placement, rolling, and quality assurance, among others. Pot holes and rust, if any, are removed from the existing surface. At least a week before installing the surface course, the imperfections are filled in using premix chippings. If the existing pavement is significantly rutted, a thick enough bituminous levelling course is used to install a bituminous concrete surface course on a binder course rather than directly on a WBM. Tuck Coat Application The AC layer should be laid over a bituminous foundation or binder course. A tack coat of bitumen is applied at a temperature of 6.0 to 7.5 degrees Fahrenheit.
The premix is made in a hot mix factory with the necessary capacity and quality control. The bitumen can be heated to 150–177°C, and the aggregate temperature should not range from the binder temperature by more than 14°C. The transporters collect the hot mixed material, which is then transported to the place and spread by a mechanical paver at a temperature of 121 to 163 degrees Celsius. The camber of the layer and its thickness are precisely measured. The temperature control during mixing and compaction has a significant impact on the strength of the final pavement structure. Rolling around When a mix is placed on the base course, it is compressed thoroughly.
Preparation and placing of Premix
The first or break down rolling is done with an 8 to 12 tonne roller, and the intermediate rolling is done with a 15 to 30 tonne fixed wheel pneumatic roller with a 7kg per sq.cm tyre pressure. The roller’s wheels are kept wet with water. The number of passes necessary is determined on the layer thickness. If the initial rolling was not sufficient in hot weather, rolling the next day helps to improve the density. A tandem roller of 8 to 10 tonnes is used for the final rolling or finishing. Road Construction Tandem Roller Tandem Roller Bituminous concrete construction quality control on-site routine checks are performed to assure the quality of the finished pavement.
The temperature of the paving mix as it is being mixed and compacted. For every 100 tonnes of mix released by the hot mix plant, at least one sample is collected and tested for the above requirements. There are also Marshall exams. One test of the field density is undertaken for every 100 sq.m of compacted surface to ensure that it is at least 95% of the density obtained in the laboratory. The maximum thickness variation permitted is 6mm per 4.5m length of construction. The finished look Putting the Finishing Touches to a Road A 3.0 m straight edge should be used to inspect the AC surface. In a length of 300 metres, the longitudinal undulations should not exceed 8.0 mm, and the number of undulations higher than 6.0 mm should not exceed 10.
The first phase in the Bitumen Road Construction Steps is preparation. It is the removal of hard rocks, stone holes, dust, and other debris from surfaces. Fill the irregular surface with 12 mm to 40 mm particles. Coarse aggregates are used to fill in big uneven surfaces. These fillings must be completed prior to the application of the surface course. Construction of Bitumen Roads: A Step-by-Step Guide Bitumen Road Construction Steps: Application of Coats The Bitumen Road is the second key step. The application of coatings is one of the construction processes. To put on a ready surface, a bituminous base course and a binder course. Tuck coat is the term given to this coat. This coating can be sprayed or dispersed by hand or by machine. According to the manufacturer, these coatings cover a particular number of square metres.
Bituminous roads have a surface made of bituminous materials, which are also known as asphalt. It is a viscous, sticky dark liquid derived from natural reserves such as crude petroleum. Bituminous Surfaces of Various Types Prime Coat: This is a single coat of bituminous binder with a low viscosity. This coat is put on an untreated pervious layer such as WBM that already exists. The major goal is to strengthen the bond between the base and the bituminous surface. Functions include: The main purpose is to improve adhesion between the current pervious foundation and the worn surface. To bind dust and loose particles together in order to create a hard and durable surface. It acts as a temporary barrier, preventing surface water from reaching the surface. Tack Coat: This is a single low viscosity coat.
It refers to the application of two or more coats of bituminous materials to a prepared base. Bituminous binders are sprayed on this coat, and chipped aggregates are correctly rolled. Its purpose is to prevent the release of binding material as well as road damage caused by waterproofing effects. Roads can be quickly cleaned and washed, which decreases the amount of dust. The wear and tear on tyres is reduced by a smooth road surface. Steps & Procedures for Bituminous Road Construction: Penetration of Bituminous Materials Road Macadam: The aggregates are held together in this form of bituminous road by grouting bitumen into the voids of the compacted particles. This type of bituminous road is commonly used in 50 and 75 mm thicknesses.
First, dust and other debris are removed from the surface where bitumen macadam will be applied. The road’s gradient and camber have been thoroughly examined. If necessary, a primer coat might be applied to permeable surfaces. Spreading Course Aggregates: Aggregates can be spread manually or mechanically. Template cat or camber profiles can be utilised to achieve the desired profile in cross-section. Rolling: After the aggregates have been speeded, they are dry rolled with a roller weighing at least 10 tonnes. It is guaranteed that the aggregates are compacted and interlocked appropriately. Bitumen Application: Using a pressure distributor or a mechanised hand sprayer, a homogeneous layer of bitumen binder is sprayed to the dry rolled compacted aggregates.
Once the bitumen has been poured appropriately, critical aggregates are laid properly, and the rolling operation is resumed for proper compaction. At the same time, the Cross Profile is examined. Seal Coat Application: If the road will be opened to traffic and no other surface course is necessary, the seal coat will be applied. It may be made of sand bitumen or a sort of surface dressing. Finishing: The road’s cross profile should be examined using a template, and the longitudinal profile should be checked using the road’s straight edge. On a 3 m road, 12 mm of undulation is allowed. Open to Traffic: The road is open to traffic when a minimum of 24 hours has passed since it was built.
If potholes or depressions are discovered in the existing layer, they must be filled with percolated chippings before the carpet layer is put. The tack coat is applied to the WBM or old bitumen surface after the surface has been prepared. If there are any softer aggregates present, such as laterite, kankar, or murum, a primer coat should be applied first. Tack Coat Application: After heating the bitumen binder to the desired temperature, a tack coat is applied to the surface. Premix Preparation and Placement: Premix is prepared using a mechanical rotary mixer or a hand drum mixer. Aggregates and bitumen are cooked separately for this mix at a specific temperature. The mixing is carried out in order to.
preparation of base course, application of bituminous coat, placement of bituminous mix, rolling and check for quality etc.
Bituminous pavements are constructed in different layers such as base course.
Asphalt bitumen is a binding organic material made from the by-products of refined crude oil.