Publications

Displaying 51 - 75 of 80

Effect of sample conditioning on the water absorption of concrete

August 1, 2011

Author(s)

Javier Castro, Dale P. Bentz, Jason Weiss

ASTM C1585 is commonly used to determine the absorption and rate of absorption of water in unsaturated hydraulic cement concretes. ASTM C1585 preconditions the samples for a total of 18 days. Unfortunately however, the range of relative humidities that can

Examining Capillary Depercolation in Cement-Based Materials: Measurement Techniques and Parameters which Influence their Interpretation

May 31, 2011

Author(s)

G Sant, Dale P. Bentz, Jason Weiss

The connectivity of the porosity in cement-based materials has an impact on material durability, the interpretation of experimental measurements such as chemical shrinkage, and the timing of curing operations. While several techniques have been used to

Effect of Initial Scarification and Overlay Treatment Timing on Chloride Concentrations in Concrete Bridge Decks

May 23, 2011

Author(s)

W. S. Guthrie, Curtis Nolan, Dale P. Bentz

Scarification and overlay (SO) procedures are often performed on concrete bridge decks to minimize the corrosion of reinforcing steel due to chloride ingress. Given the need to develop guidelines for the initial timing of SO treatments, the objectives of

Evaluation of Sustainable High-Volume Fly Ash Concretes

January 1, 2011

Author(s)

Alejandro Duran-Herrera, Cesar Juarez, P Valdez, Dale P. Bentz

This article presents results of an experimental research work oriented to develop practical tools for the regional concrete industry, as well as to illustrate the potential benefits of the synergistic effect of an ASTM C 618 Class F fly ash (FA) produced

A Dual Concentric Ring Test for Evaluating Residual Stress Development Due of Restrained Volume Change

September 1, 2010

Author(s)

John Schlitter, Andrew Senter, Dale P. Bentz, Tommy Nantung, Jason Weiss

The standard restrained ring test (ASTM 1581-04) is a simple, economical method to evaluate a concrete mixture s susceptibility of shrinkage cracking. Unfortunately, the test only provides restraint against samples that shrink and can not be used to

LWA Absorption and Desorption: The Influence on the Microstructure and Transport Properties of Internally Cured Mortars

September 1, 2010

Author(s)

Javier Castro, Ryan Henkensiefken, Tommy Nantung, Dale P. Bentz, Jason Weiss

The increased propensity for shrinkage cracking in low water-to-cement ratio (w/c) concrete has resulted in the development of new methods that can reduce the risk of early-age cracking, including internal curing. Internal curing can use water-filled

CT Measurements of SAP Voids in Concrete

August 15, 2010

Author(s)

Sara Laustsen, Dale P. Bentz, Marianne Hasholt, Ole M. Jensen

This paper describes how X-ray computed tomography (CT) scanning can be used to determine the void distribution in hardened concrete. Three different approaches are used to analyse a binary data set created from CT measurement. One approach classifies a

Planar Image-Based Reconstruction of Pervious Concrete Pore Structure and Permeability Prediction

July 1, 2010

Author(s)

Milani S. Sumanasooriya, Dale P. Bentz, Narayanan Neithalath

Transport properties of porous materials such as pervious concretes are inherently dependent on a variety of pore structure features. Empirical equations are typically used to relate the pore structure of a porous material to its permeability. In this

ADVANCES IN PORE STRUCTURE CHARACTERIZATION AND PERFORMANCE PREDICTION OF PERVIOUS CONCRETES

May 3, 2010

Author(s)

Narayanan Neithalath, Dale P. Bentz, Milani S. Sumanasooriya

Pervious concrete is receiving renewed interest as a sustainable construction material for parking lots, sidewalks, and low-traffic-volume roads. A key characteristic of this material is its coarse porosity, achieved by omitting the fine aggregates from a

The Influence of Shrinkage-Reducing Admixtures (SRAs) on Moisture Absorption in Cementitious Materials at Early Ages

March 1, 2010

Author(s)

G Sant, A Eberhardt, Dale P. Bentz, W Weiss

The water absorption behavior of cement pastes (w/c = 0.30) containing varying concentrations (i.e., 0 %, 0.2 % and 5 %) of a shrinkage reducing admixture (SRA) was measured. Moisture ingress was monitored using x-ray absorption. A decrease in both the

Plastic Shrinkage Cracking in Internally Cured Mixtures Made with Pre-wetted Lightweight Aggregate

February 1, 2010

Author(s)

Ryan Henkensiefken, Peter Briatka, Dale P. Bentz, Tommy Nantung, Jason Weiss

The incorporation of pre-wetted lightweight aggregates (LWA) has been used to reduce the shrinkage cracking associated with self-desiccation in the hardened state. Little research however exists which shows the influence of internal curing on the formation

Water Absorption in Internally Cured Mortar Made with Water-Filled Lightweight Aggregate

October 1, 2009

Author(s)

Ryan Henkensiefken, Javier Castro, Dale P. Bentz, Tommy Nantung, Jason Weiss

The increased propensity for shrinkage cracking in low w/c concrete has spawned the development of new technologies that can reduce the risk of early-age cracking. One of these is internal curing. Internal curing uses saturated lightweight aggregate to

Internal Curing Improves Concrete Performance throughout its Life

September 1, 2009

Author(s)

Ryan Henkensiefken, Javier Castro, Haejin Kim, Dale P. Bentz, Jason Weiss

Internal curing (IC) provides a set of water reservoirs within the concrete to prevent self-desiccation and promote hydration. While early research in this area focused on reductions in early-age deformation and cracking, recent efforts have demonstrated

Volume Change and Cracking in Internally Cured Mixtures Made with Saturated Lightweight Aggregate under Sealed and Drying Conditions

August 3, 2009

Author(s)

Ryan Henkensiefken, Dale P. Bentz, Tommy Nantung, Jason Weiss

Increased occurrences of early-age shrinkage cracking in low water to cement ratio (w/c) concrete have spawned innovative developments in mixture design that reduce the risk of cracking. One such development is internal curing, which utilizes the inclusion

Predicting the Permeability of Pervious Concretes from Planar Images

May 1, 2009

Author(s)

Milani S. Sumanasooriya, Dale P. Bentz, Narayanan Neithalath

This paper discusses the reconstruction of three-dimensional material structures of pervious concretes using two-dimensional digital images obtained from actual specimens, and computational permeability predictions using these reconstructed three

Relationship Between Engineering Properties, Mineralogy, and Microstructure in Cement-Based Hydroceramic Materials Cured at 200 C to 350 C

March 1, 2009

Author(s)

Konstantinos Kyritsis, Christopher Hall, Dale P. Bentz, Nicola Meller, Moira A. Wilson

Cement-based materials used to seal geothermal or deep oil wells are exposed to severe conditions. Optimizing engineering properties such as strength and permeability is therefore very important. We have synthesized hydroceramic materials for such

IDENTIFYING THE FLUID-TO-SOLID TRANSITION IN CEMENTITIOUS MATERIALS AT EARLY AGES USING ULTRASONIC WAVE VELOCITY AND COMPUTER SIMULATION

February 1, 2009

Author(s)

G Sant, Dale P. Bentz, W Weiss

Assessing the fluid-to-solid transition in cementitious systems at early-ages is crucial for scheduling construction operations, determining when laboratory testing can begin, and for assessing when computer simulations of shrinkage stress should begin

Mitigating Autogeneous Shrinkage by Internal Curing.

December 1, 2004

Author(s)

M R. Geiker, Dale P. Bentz, O M. Jensen

Pumice Aggregates for Internal Water Curing.

December 1, 2004

Author(s)

Pietro Lura, Dale P. Bentz, D A. Lange, K Kovler, A Bentur

Suspended Hydration and Loss of Freezable Water in Cement Pastes Exposed to 90% Relative Humidity

November 1, 2004

Author(s)

Kenneth A. Snyder, Dale P. Bentz

Degree of hydration and differential scanning calorimetry (DSC)measurements characterize the effect of a 90 % relative humidity (RH) environmental exposure on early cement paste hydration. Cement paste specimens 1.6 mm thick and with water-cement mass

Pumice Aggregates for Internal Water Curing

March 17, 2004

Author(s)

Pietro Lura, Dale P. Bentz, D Lange, K Kovler, A Bentur

A novel concept in internal curing of High Performance Concrete is based on dispersing very small, saturated lightweight aggregates (LWA) in the concrete, containing sufficient water to counteract self-desiccation. The amount of water in the LWA can be

Measurement of Water Transport from Saturated Pumice Aggregates to Hardening Cement Paste

August 6, 2003

Author(s)

Pietro Lura, Dale P. Bentz, D Lange, K Kovler, A Bentur, K Van Breugel

In this study about internal curing of High Performance Concrete, X-ray absorption showed that considerable transport of water from saturated lightweight aggregates (pumice) to hydrating cement pastes (w/c ratio 0.3) took place in the first days after

Effects of the Incorporation of Municipal Solid Waste Incineration Fly Ash in Cement Pastes and Mortars. II: Modeling

April 1, 2002

Author(s)

S Remond, Dale P. Bentz, M. Pimpinella

This work falls within the scope of a general problem of the assessment of concretes manufactured from waste materials. The main objective is to study the long-term evolution of these materials during leaching using the cellular automata- based hydration

Stoichiometry of Slag Hydration With Calcium Hydroxide

April 1, 2002

Author(s)

J M. Richardson, Joseph J. Biernacki, Paul E. Stutzman, Dale P. Bentz

The stoichiometry of the reaction between ground granulated blast furnace slag (GGBFS) having an empirical formula of C 7.d88^ S 7.39 and calcium hydroxide (CH) was investigated. Scanning electron microscopy (SEM) was used to determine the slag consumption

Concrete Optimization Software Tool User's Guide

July 1, 2001

Author(s)

M J. Simon, Dale P. Bentz, James J. Filliben

This user's guide provides instructions for and examples of using the Concrete Optimization Software Tool (COST), a joint product of the Federal Highway Administration and the National Institute of Standards and Technology. COST provides an internet-based

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