What is DLC and PQC?

PQC stands for Pavement Quality Concrete made with larger size aggregates following IRC specifications and laid over a Dry Lean Concrete(DLC), concrete subbase course. PQC construction is explicitly used for highway concrete pavements and runway pavements to take heavy loads.

What is PQC?

Pavement Quality Concrete (PQC) is normally employed for providing a strong surface of rigid pavements. PQC is also used for construction of runways in airports in order to distribute the heavy impact load from wheel to sub- grade layers [1].

What is DLC in road construction?

Dry Lean Concrete (DLC) is an important part of modern rigid pavement. It is a plain concrete with a large ratio of aggregate to cement than conventional concrete and generally used as a base/sub base of rigid pavement.

What is pavement DLC?

The current practices of the construction of cement concrete road for highways in India require a layer of dry lean concrete (DLC) as a base course over which pavement quality concrete slabs rest. It is one of the common and popular cement treated sub-base/base for concrete pavements.

What is PQC process?

Pavement Quality Concrete (PQC) is cement concrete made with large size aggregates in accordance with IRC specifications and laid over a dry lean concrete sub-base. This construction is used specifically for highway concrete pavements and for airport runway pavements as it can take heavy loads.

Dry Lean Concrete (DLC) layer for PQC road

What is the ratio of PQC?

A control mix for PQC was prepared with 400 kg/m³ of ordinary Portland cement (OPC) and water–cement (w–c) ratio of 0.40. Other concrete mixtures were then prepared by substituting 20%, 40%, 60%, 80% and 100% copper slag in control mix.

What is the grade of DLC?

Mix Ratio of Lean Concrete

M-7.5 grade concrete will give a total characteristic strength of 7.5 MPa. M-10 grade concrete will give a total characteristic strength of 10 MPa.

What is GSB road?

Granular Sub-base (GSB) consists of laying and compacting well graded material on prepared sub-grade in accordance with the specifications.: GSB layer is intermediate layer in between Sub-grade and Wet mix macadam. GSB layer is laid in roads and higway works due to its properties .

Why dry lean concrete is used?

Dry Lean Concrete is a mixture in which the amount of cement is less than the amount of liquid that is present in the layers. This makes it ideal as a base layer on which other types of concrete are placed on top. It is good for a flat surface on uneven or dirty terrain.

What is CRM in road construction?

CRM is a mixture of bitumen and modified bitumen rubber is intrusive. The viscosity modifier rubber used asphalt binder and temperature resistance as well as resistance against brittle at low temperatures increases. CRMB has good adhesion to mineral mass, and thereby reduce brittleness and deformity.

What is DBM road?

Engineering. Dense Bituminous Macadam (DBM) is a binder course used for roads with more number of heavy commercial vehicles and a close-graded premix material having a voids content of 5-10 per cent.

What is screening in WBM?

WBM road means water bound macadam road. The wearing surface of WBM road consist of clean and crushed aggregates which are mechanically interlocked by rolling operation. The material is bound with filler material (which are also called as screenings) and water, laid on prepared base course.

What is the grade of concrete in PQC?

Generally it is designed in High Grade (M-35 to M-50) and designed for 32mm size aggregates and low slump. Materials Required:- The Following materials are required for Construction of PQC Road.. Ordinary Portland Cement (IS 269), Portland Pozzolana Cement (IS 459) & Portland Slag Cement (IS 1489) Can be used for PQC.

What is RCC road?

Roller compacted concrete (RCC) is a tough, durable type of concrete pavement that is well suited for heavy industrial applications, as well as low-speed roads and arterial roads. Roller compacted concrete draws its name from the construction practices used to place and finish the material.

What is PQ concrete?

Pavement Quality Concrete (PQC) A cement concrete of a suitable quality for use as the surfacing on airfield pavements.

What is C5 concrete used for?

C5/8 Concrete

Used in both commercial and domestic projects, C5 or C8 is a wet lean mix concrete. It is an ideal option for foundations and blinding when you are working on a residential project. Besides, it is also common among builders, when it comes to working on curb bending.

What is difference between lean concrete and PCC?

The main difference between lean and PCC concrete is that lean concrete contains less cement compared to the water content present in it. This means, when compared to plain cement concrete (PCC), the lean concrete has a smaller ratio of cement to water content.

What is WBM and WMM?

WBM(Water Bound Macadam) conventional method and WMM(Wet Mix Macadam) modern technology- are base course layers for Pavement/Road design. In case of WBM stone aggregates and binders are overlaid on one another at the time of construction.

What is minimum thickness of GSB?

➢The recommended minimum thickness of granular base is 225 mm for traffic upto 2 msa and 250 mm for traffic exceeding 2 msa.

Why WMM is used?

The WMM roads are said to be more durable. The WMM roads get dry fast and can be opened for traffic within less time as compared to the WBM roads, which take about one month for getting dry. WMM roads are soon-ready to be blacktopped with the Bituminous layers. WMM roads are constructed at a faster rate.

What is the minimum thickness of lean concrete?

The mudmat provides a working surface for the construction of the concrete foundation mat; the mudmat has a minimum thickness of 12 inches of un- reinforced concrete.

What is rich mix concrete?

A rich mixture contains a high proportion of cement. A lean mixture is a mixture of concrete or mortar with a relatively low cement content. A harsh mixture of concrete is one without mortar or aggregate fines, resulting in an undesirable consistency and workability.

What is rigid pavement?

Rigid pavements are constructed of portland cement concrete slabs resting on a prepared subbase of granular material or directly on a granular subgrade. Load is transmitted through the slabs to the underlying subgrade by flexure of the slabs.