Author: Spencer Ray BoylePublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Evaluation of Recycled Concrete for Use as Aggregates in New Portland Cement Concrete Pavements
Author: Spencer Ray BoyleEvaluation of Recycled Concrete as Aggregate in New Concrete Pavements
Author: Evaluation of Recycled Concrete for Use as Aggregates in New Concrete Pavements
Author: Daniel Gilbert MjeldePortland Cement Concrete Recycling
Author: R. Gordon McKeenPublisher:
ISBN:
Category : Pavements, Concrete
Languages : en
Pages : 142
Book Description
The review of current technology pertaining to the recycling of existing portland cement concrete pavements was conducted. The purpose was to assess the applicability of recycling to U.S. Air Force pavement rehabilitation work. Costs of alternatives were reduced to simple models for use in evaluating sensitivity to cost factors. A study of projects on which this technology was used identified aggregate cost and haul distance as key factors.
Evaluation of Recycled Portland Cement Concrete Pavements for Base Course and Gravel Cushion Material
Author: Allen L. CooleyPublisher:
ISBN:
Category : Pavements
Languages : en
Pages : 106
Book Description
Based upon the work conducted in this study, it was concluded the recycled portland cement concrete pavements are available as an option for the construction of gravel cushion and aggregate base course layers.
Evaluation of Recycled Concrete Aggregate Produced from Demolished Runway Panels as a Substitute for Coarse Aggregates in New Portland Cement Pavements
Author: Timothy Charles SpryRecycling of Portland Cement Concrete Pavements
Author: William A. YrjansonPublisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 60
Book Description
This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for recontstructing portland cement concrete (PCC) pavements. Information is provided on the processes and procedures used by a number of states in using PCC pavement as aggregate in reconstructed concrete pavement. Since 1975 a number of state highway agencies have reconstructed concrete pavements using the old PCC as aggregate in the new pavement. This report of the Transportation Research Board describes the processes used on various projects in several states, giving details of construction procedures, as well as test results on various properties of the recycled aggregates and the resultant concrete.
Evaluation of Low-quality Recycled Concrete Pavement Aggregates for Subgrade Soil Stabilization
Author: Masoumeh TavakolPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Recycled concrete aggregate (RCA) is the byproduct of the demolition of concrete structures and pavements. An estimated 140 million tons of concrete waste is produced annually in the United States, most of which ends up in landfills. The use of RCA to replace quarried aggregates in paving projects is one way to utilize these materials and alleviate concerns regarding this increasing waste stream. RCA usage prevents waste concrete disposal into landfills, resulting in more sustainable use of mineral aggregate sources, and may further reduce costs associated with paving projects. However, the inferior physical properties of RCA, such as the presence of recycled mortar, complicate the incorporation of RCA into new concrete mixtures. State highway agencies such as the Kansas Department of Transportation are facing further issues with RCA from D-cracked pavements, raising the question if D-cracked aggregates should be used in paving operations. No known work has evaluated the effect of RCA from D-cracked pavements in subgrade soil stabilization. This study stabilized a low-plasticity clay in Kansas using RCA and three stabilizing materials (lime, Class C fly ash, and a combination of Portland cement and fly ash). Candidate mixtures with varying proportions of chemical stabilizers and D-cracked aggregates were evaluated using the standard Proctor, unconfined compressive strength, linear shrinkage, and California Bearing Ratio tests. Microstructure characteristics of selected mixtures were explored using scanning electron microscopy (SEM) and energy dispersive X-ray tests. Laboratory test results indicated that RCA, in conjunction with all cementitious materials except lime, improved clay strength, stiffness, and shrinkage properties. SEM results indicated that RCA caused a low void space and a dense arrangement of soil particles. RCA effectively improved evaluated mixture properties when an adequate soil-RCA bond was reached using chemical agents. The long-term performance of full-depth flexible pavements with stabilized mixtures as subgrade was assessed in the AASHTOWare Pavement ME Design (commonly known as MEPDG) software. The life-cycle cost of flexible pavements with stabilized mixtures was estimated for a 40-year design period. Economic analysis results indicated that RCA was cost effective only if it was used with a combination of fly ash and Portland cement.
Recycling of Portland Cement Concrete Pavement
Author: John B. WojakowskiPublisher:
ISBN:
Category : Pavements, Concrete
Languages : en
Pages : 32
Book Description
The recycling of portland cement concrete pavements (PCCP) can help alleviate any material disposal problems during construction, especially in urban areas and reduce the consumption or importation of virgin aggregate into aggregate poor areas. Two test sections using the coarser fraction from the original crushed PCCP were placed on K-7 in 1985. One section incorporated a recycled base and standard PCCP construction; another section was designed as a recycled base and recycled PCCP. Two other sections were control sections constructed with regular aggregate.
Design and Control of Concrete Mixtures
Author: Steven H. KosmatkaPublisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 224
Book Description
Portland Cement Association reference, dealing with fundamentals, cold weather concreting, curing, admixtures, aggregates, mixing, and much more.