The treatment of subgrades with hydraulic binders is designed to increase the bearing capacity of the roadbed significantly. It thus offers a better support to the worksite traffic and the subgrade can be taken into account in the overall structural design of the pavement. The economic stakes are thus evident....
Cycling on Peat
A cycle track had to be laid quickly on a poor load-bearing subsoil, 18 m of peat. The usual design would have caused excessive subsidence and damage to the adjacent road. The chosen solution was a "floating" structure. In the design the upward pressure of the groundwater was considered to...
The Influence of Composition and Compaction on the Properties of Roller Compactcd Concrete
In many countries rullw cumpactod concrete (RCC) proved to be a success as a construction method for highly stressed industrial floors, for concrete pavements, subbases for concrete pavements and asphalt surfaces. Since 1993 the Research, Development and Consulting Department of tho Heidelberger Zement AG is attended with a research project...
A New Assortment of Cement (CD 40-A) Meant for Concretes for Roads, Motorways and Airport Runways
The use of CD 40-A cement eliminates the classical procedures of measuring plastifying and air entraining additives at the preparation on site of the road concrete. The article presents the main characteristics of CD 40-A and the results of laboratory tests carried out to establish the influence of this type...
Surface Characteristics of a Recently Constructed Concrete Motorway in the UK
A full-scale trial has been constructed in the UK in which concrete surfaces with brushed, tined bnd exposed aggregate textures have been compared with traditional hot rolled asphalt. The concrete surfaces were applied to a 250 mm thick, continuously reinforced concrete pavement laid by railmounted paving equipment. The exposed aggregate...
Design and Construction of a Concrete Pavement on Compressible Muds
This paper deals with the design, construction and performance of a freeway section over a thick layer of compressible mud. Halfway on the Madrid to Zaragoza freeway, in the valley of the Jalón River, several very soft clayey deposits were found, originated by endorreic drainage basins. The ground treatment systems...
Concrete Pavements in Seasonal Frost Conditions – Finnish Experience of the Durability and Economy of a Concrete Pavement Built in 1990 in Northern Finland
Oulu is a city of about 145,000 inhabitants including its suburban area located in northern Finland where the winter can be very cold. The freezing index is about 40,000 °C h (once in 10 years) and the frost penetration depth can be about 2 m or rluuue. lii 1990, 4...
Application of One Day Concrete for Pavements
In order to shorten the construction periods of concrete structures, PWRI and four cement manufacturers carried out a joint research to develop 5 new types of one-day concrete with the following requirements: The compressive strength of the concrete shall be 30 N/mm 2 or more one day after mixing as...
The Utilization of Tarbearing Scarified Road Materials with Special Hydraulic Binders
The utilization of tarbearing scarified road materials, which are charged with phenols and polycyclic aromatic hydrocarbon (PAH) to a considerable extent, is becoming a problem of increasing urgency in Germany. This paper deals with the consolidation of tarbearing scarified road materials with a special hydraulic binder, which due to its...
First Experimental Application of Deactivated Coloured Concrete in Belgian Road Construction
Deactivated coloured concrete is characterized mainly by two factors: its colouring and its surface treatment. Colouring is achieved by using preferable coloured aggregates and admixing the mortar with a dye. The surface treatment consists of chemical aggregate exposure. A first major experiment in Belgium combining coloured concrete and chemical aggregate...
A New Mix Design Methodology for Roller Compacted Concrete, with Case Studies
A new mix design methodology for roller compacted concrete (RCC) is described that involves preparing low and high density specimens at various (typically three) cement contents. For each specimen density is determined. Strengths (compressive and/or split tensile) are measured at various intervals (e.g., 1, 4, 7 and 28 days). Multiple...
Mix Design for Concrete Pavements Durability Options Based on the New European and Italian Standards
The provisions of the European Prestandard ENV 206 "Concrete - Performance, Production, Placing and Compliance Criteria" place the accent on the qualitative requirements (physical, chemical and mechanical ones) of a durable road concrete. The theoretical life of a rigid road pavement obviously r1.pends on the design and the quality control...