Recyclingmaterials and industrial by-products are suitable for building purposes if the constructions made of them adequately withstand all loads occuring during the scheduled period of utilization and if they do not affect the environment unac-ceptably. Therefore the evaluation of recycling-and secondary materials must cover both the cons-tructional and the ecological...
Reuse of Crushed Concrete as a Road Base Material
Aggregates from crushed road concrete were tried in 7 test sections, and 84 samples from some lOcrushing plants were :ested in the laboratory. lt has been shown that aggregates suitable for re-use in sub-Jases or road bases can be produced not only in fixed plants butalso by small mobile crushers,...
Economic Analysis of Cement Fly Ash Bound Materials
In order to design a cement bound mixture for use in base/sub-base pavement layers, it isusually re-quired to obtain a certain minimun strength value.Ifonly one type of binder isused, the problem hasonly one restriction and one variable, so, one onlysolution. However, if more binders are added tothe mixture, asit happens...
Design of Sand-Cement Base Courses Using Fracture Mechanics Principles
Sand-cement base courses exhibit shrinkage and fatigue crack-ing. Both types of cracks tend to reflect through the asphaltictop layers. An analysis has been made to determine pavementlife, which is defmed as the number of cycles until cracks arevisible at the pavement surface, by taking into account fatiguecrack initiation, propagation and...
The Road Retreatment Plant Arc 700
The retreatment of old cement pavement is an old technique hat needed rustic equipment coming from agricultural equip-nent or very often meant for the stabilisation in place of fine.oils.faking into account the scatter of measuring out of Portland:ement, the lack of power and efficiency of the mixing equip-nent, this technique...
Aspects of Mechanistic Analysis of Lightly Cementitious Pavement Materials
Inthispaper compressionfailureasa resultof traffic loading in lightly cementitious pavement ma-terials is discussed. The investigation was donewith the aid of mechanistic analysis, and includesboth surface and depth deflection measurementson an actual pavement from which linear elasticmoduli values were backcaIculated. This wasdone to evaluate the «actual» stresses between therelatively thin surfacing and...
Lime-Cement Stabilization of Wet Cohesive Soils
When treated with lime, wet cohesive soils granulate and be-ome more workable, thus allowing easier subsequent incor-oration of cement.'he effects of pregranulation with lime on various aspects ofement stabilization were investigated: compaction. CBR bear-19 capacity, strength values, durability, the effects of differentariables such as density and moulding moisture content. Theitter...
Some Theoretical and Practical Aspects of the Use of Fly Ash in Lean Concrete
Until a few years ago, interest in the incorporation of fly ash into lean concrete was rather limited. A study conducted in the laboratory has demonstrated some of the advantages of the technique and shown that the optimum dosage is of the order of5 %. In Belgium, mixtures of this...
Cement Grouted Macadam
Cementgrouted macadam (CM) is a 150-200 mm thick baselayer of macadam, 32-65 mm, which is stabilized to full homogeneity with a cement-slurry composed by cement, sand, flyash, air-entrainer, a superplasticizer and water. The cement-slurry is spread out by a especially equipped caterpillar-tracked asphalt-paver.
The Use of Urban Solid Waste Slags in Soil Cement and Cement Bound Granular Materials
Researchers and Technicians have ascertained that the use of ppropriate substitution materials in cement stabilizations and nixtures during the construction of road-base, sub-base and oundation layers allows to simultaneously fulfill technical-tructural, economical and environmental-ecological require-nents,~s an alternative by-product, Urban Solid Waste Ashes and:lags have been tested in a laboratory in...
Modern Construction of Concrete Pavements For Expressways in Spain
In this paper, basic characteristics of concrete pavements constructed in Spain during the last years, corresponding to the General Highway Plan 1984-1991, are described. The main solutions adopted to get a concrete pavement with high strength and appropriate texture are an~)ed. The solutions used in the construction in cold weather...
Novel Developments in the Quality Assurance of Road Construction Projects
Quality assurance (QA) in its traditional meaning is based on very detailed, in general prescriptive design and construction standards, on standardi-zed conformity criteria for all construction mate-rials and on generally accepted rules for good cons-truction practice. This basis allowed to limit QAon control tests and acceptance decisions for in-termediate or...