Early Age Strength Assessment of Cement-treated Basematerials

Early Age Strength Assessment of Cement-treated Basematerials
Author: Tyler Blaine Young
Publisher:
Total Pages: 78
Release: 2007
Genre: Pavements
ISBN:

In order to avoid the occurrence of early-age damage, cement-treated base (CTB) materials must be allowed to cure for a period of time before the pavement can be opened to traffic. The purpose of this research was to evaluate the utility of the soil stiffness gauge (SSG), heavy Clegg impact soil tester (CIST), portable falling-weight deflectometer (PFWD), dynamic cone penetrometer, and falling-weight deflectometer for assessing early-age strength gain of cement-stabilized materials. Experimentation was performed at four sites on a pavement reconstruction project along Interstate 84 near Morgan, Utah, and three sites along Highway 91 near Richmond, Utah; cement stabilization was used to construct CTB layers at both locations. Each site was stationed to facilitate repeated measurements at the same locations with different devices and at different curing times.

Early-age Strength Assessment of Cement-treated Materials

Early-age Strength Assessment of Cement-treated Materials
Author: Tyler Blaine Young
Publisher:
Total Pages: 78
Release: 2007
Genre: Electronic dissertations
ISBN:

In order to avoid the occurrence of early-age damage, cement-treated base (CTB) materials must be allowed to cure for a period of time before the pavement can be opened to traffic. The purpose of this research was to evaluate the utility of the soil stiffness gauge (SSG), heavy Clegg impact soil tester (CIST), portable falling-weight deflectometer (PFWD), dynamic cone penetrometer, and falling-weight deflectometer for assessing early-age strength gain of cement-stabilized materials. Experimentation was performed at four sites on a pavement reconstruction project along Interstate 84 near Morgan, Utah, and three sites along Highway 91 near Richmond, Utah; cement stabilization was used to construct CTB layers at both locations. Each site was stationed to facilitate repeated measurements at the same locations with different devices and at different curing times.

Guide to Cement-treated Base (CTB)

Guide to Cement-treated Base (CTB)
Author: Gregory E. Halsted
Publisher:
Total Pages: 20
Release: 2006
Genre: Pavements
ISBN: 9780893122539

Cement-treated base (CTB) is a general term that applies to an mixture of native soils and/or manufactured aggregates with measured amounts of portland cement and water that is compacted and cured to form a strong, durable, frost resistant paving material. Other descriptions such as soil-cement base, cement-treated aggregate base, cement-stabilized base are sometimes used. This document provides a basic guide on the use of cement-treated base (CTB) for pavement applications. This document provides on overview on the design and construction of CTB for both mixed-in-place and central plant mixed operations. A suggested construction specification is also included.

Field Application of the PM Device and Assessment of Early Age Behaviors of Cement Stabilized Pavement Layers

Field Application of the PM Device and Assessment of Early Age Behaviors of Cement Stabilized Pavement Layers
Author: W. Griffin Sullivan
Publisher:
Total Pages: 204
Release: 2021
Genre:
ISBN:

Cement stabilized material used for subbase or base pavement layers has been a widely accepted practice by many state Departments of Transportation (DOTs); particularly, for DOTs with limited access to quality crushed aggregates for pavement construction. Despite over 100 years of use, construction specifications governing cement stabilized pavement layers have largely remained the same and are primarily method based specifications (i.e. individual components evaluated and construction methods prescribed) rather than evaluating or testing mechanical properties of the end product. With the recent emergence of the Plastic Mold compaction Device (PM Device), multiple agencies are looking to depart from method based soil-cement specifications by implementing the PM Device for design and construction quality control and quality assurance (QC/QA) testing. Prior to this dissertation, PM Device protocols have been validated under lab conditions but only limited field validation had been performed. Additionally, time delay between initial mixing and compaction of cement stabilized soils is a known issue, which can affect compaction of PM Device specimens as well as construction target density values determined through AASHTO T134 Proctor testing. The main objectives of this dissertation are to investigate time delay effects on cement stabilized soil compactability during Proctor testing, develop a nationally recognized Standard Practice for PM Device specimen fabrication, and perform PM Device field evaluations for QC/QA testing. Lab experiments were conducted to investigate time delay effects and finalize PM Device Standard Practice protocols. Five field projects were evaluated to validate PM Device QC/QA applications and Standard Practice protocols in a construction environment. Time delay was observed to have a notable detrimental influence on compactability during AASHTO T134 Proctor testing and PM Device specimen fabrication. Recommended guidance was provided to characterize compaction delay effects. AASHTO PP92-19 was developed and published by AASHTO's Committee on Materials and Pavements to standardize specimen fabrication for the 3x6 inch and 4x8 inch versions of the PM Device. The PM Device fared well for construction activities when benchmarked relative to density, strength, and modulus of cores taken from constructed cement stabilized pavement layers. The PM Device was recommended for implementation consideration by state DOTs and other agencies.

Early Assessment of Concrete Quality by Accelerating Compressive Strength Development with Heat (Results of ASTM's Cooperative Test Program)

Early Assessment of Concrete Quality by Accelerating Compressive Strength Development with Heat (Results of ASTM's Cooperative Test Program)
Author: MH. Wills
Publisher:
Total Pages: 12
Release: 1975
Genre: Accelerating (chemistry)
ISBN:

Rapid concrete construction practices have led to increasing pressure to assess the quality of concrete at a very early age.Therefore, a cooperative test program was conducted among nine laboratories to evaluate several existing test procedures involving the use of either hot water, boiling water, or the heat of hydration of portland cement to provide heat necessary to accelerate the compressive strength development of concrete.Depending upon which procedure was employed, the amount of acceleration ranged from 1.1 to 2.5 times the strength developed after the same period of moist curing.Statistical analyses of the data justified adoption of a standard method that can be used to judge the quality of concrete soon after mixing.This method involves three procedures of accelerated curing which are limited to concrete made with the same materials and tested by the same laboratory.It has been designated ASTM C 684-74 (Making, Accelerated Curing, and Testing of Concrete Compression Test Specimens) Use of it, under the conditions stated therein, results in as reliable an evaluation of the quality of the concrete at one or two days of age as compared to that measured at 28 days of age according to ASTM C 31-69 (Making and Curing Concrete Test Specimens in the Field).