Supervisor/Foreman
Dense-Graded
A dense-graded mix is a well-graded HMA mixture intended for general use. When properly designed and constructed, a dense-graded mix is relatively impermeable. Dense-graded mixes are generally referred to by their nominal maximum aggregate size. They can further be classified as either fine-graded or coarse-graded. Fine-graded mixes have more fine and sand sized particles than … Read more
Workability
Workability is a general term used to describe the basic rheological aspects of fresh PCC (e.g., PCC in a wet, plastic state). Workability is instrumental in the proper placement and compaction of fresh PCC. In general, excessively stiff (or harsh) fresh PCC can be difficult to place and compact resulting in large void spaces and … Read more
Pavement Distress
Properly designed and maintained HMA pavements can provide many years of satisfactory service. However, like all pavements, HMA pavements can be damaged by certain conditions. This page is intended to: Assist in identifying basic HMA pavement damage. HMA pavement damage that is visible at the surface of the pavement is often called “surface distress”. Provide … Read more
Hot In-Place Recycling
Hot in-place recycling (HIR) is a less common form of hot asphalt recycling. There are three basic HIR construction processes in use, all of which involve a specialized plant in a continuous train operation (FHWA, 2001c[1]): Heater scarification (Figure 1). This method uses a plant that heats the pavement surface (typically using propane radiant heaters), … Read more
PCC Joint Construction
Location Typical joint locations are covered in the article on Joints, and are not repeated here. However, it is important to note that joint locations should be indicated on the construction plans and planned in advance (Figure 1). Intersection joint locations can be quite complex and should be marked out on the base in advance … Read more
Other Joints
Expansion, isolation and construction joints are created by formwork before the PCC is placed. Since these joints are designed to completely separate adjacent masses of PCC, they are usually made by inserting a small non-PCC piece of material such as a strip of wood. Construction Joints Construction joints, sometimes called “headers” are usually made to … Read more
Joints
Joints are purposefully placed discontinuities in a rigid pavement surface course. All types of joints are used in rigid pavement construction methods for all PCC pavement types. CRCP uses longitudinal reinforcing steel in order to limit the number of transverse contraction joints, but it still uses longitudinal joints and periodic transverse joints. Joints can be … Read more
Full-Depth Reclamation
Although referred to as “full-depth reclamation”, this process is just an extension of the basic CIR principles to the entire HMA pavement depth plus a predetermined depth of the base material. FDR can be used to depths of 300 mm (12 inches) or more but the most typical applications involve depths of between 150 and … Read more
Raveling
Description The progressive disintegration of an HMA layer from the surface downward as a result of the dislodgement of aggregate particles. Problem Loose debris on the pavement, roughness, water collecting in the raveled locations resulting in vehicle hydroplaning, loss of skid resistance Possible Causes Several including: Loss of bond between aggregate particles and the … Read more
Depression
Description Localized pavement surface areas with slightly lower elevations than the surrounding pavement. Depressions are very noticeable after a rain when they fill with water. Problem Roughness, depressions filled with substantial water can cause vehicle hydroplaning Possible Causes Frost heave or subgrade settlement resulting from inadequate compaction during construction. Repair By definition, depressions are small … Read more
Sponsors
