International Concrete Abstracts Portal

Showing 1-5 of 26 Abstracts search results

Document: 

CI3609Kolahdoozan

Date: 

September 1, 2014

Author(s):

Maryam Kolahdoozan, Medhat H. Shehata, Mohamed Lachemi, Hannah C. Schell, Stephen Senior, and Carole Anne MacDonald

Publication:

Concrete International

Volume:

36

Issue:

9

Abstract:

Unshrinkable fill is a type of controlled low strength material (CLSM) used in lieu of traditional backfill. While it is normally produced using aggregates derived from bedrock, gravel, or natural sand sources, the low maximum strength requirement indicates that alternative materials could be used. The research described in this article investigates the use of reclaimed concrete aggregate (RCA) as a sustainable and economical alternative to the newly extracted materials used in U-fill mixtures. The RCA was produced by crushing returned ready mixed concrete that had been allowed to harden.


Document: 

CI3106Lachemi

Date: 

June 1, 2009

Author(s):

Mohamed Lachemi, Khandaker M.A. Hossain, Abdurrahmaan Lotfy, Medhat Shehata, Mustafa Sahmaran

Publication:

Concrete International

Volume:

31

Issue:

6

Abstract:

Cement kiln dust (CKD) is finely divided, dry particulate material captured by the kiln’s air pollution control system. About 1.4 million tonnes (1.5 million tons) of CKD was transported to landfills in 2006 in the U.S. alone. To help develop a beneficial use for this material, two CKD-based controlled low-strength material (CLSM) mixtures were optimized for fresh and hardened properties and produced using ready mixed concrete equipment. The addition of CKD was found to improve flowability and reduce segregation and bleeding. The study demonstrates that CKD-based CLSM can be used as an alternative to conventional CLSM.


Document: 

SP242-27

Date: 

April 1, 2007

Author(s):

T. Horiguchi, T. Kikuchi, Y. Nakagawa, and K. Shimura

Publication:

Symposium Papers

Volume:

242

Abstract:

This research evaluated, from the ecological and economical points of view, the potential use of high volumes of incineration ash from sewage sludge in CLSM (Controlled Low Strength Materials). Moreover, a dust powder from crushed stone production is used as a fine aggregate. This new type of green CLSM will be a promising sustainable cementitious material for reducing CO2 emissions. In-situ early-age strength estimation of CLSM was proposed with applying simple cone penetration method (so-called YCP Test, Yamanaka Cone Penetration Test), which has been used for soil strength estimation. Test result showed that the YCP Test is found to be effective for estimating the in-situ early-age compressive strength of CLSM. Test results also showed the adequate strength development and reasonable flowability are confirmed if the mixture proportion is carefully selected. Although, the compressive strength decreases with increasing level of incineration ash, this strength reduction is easily compensated for increasing a small amount of cement content. From these tests results it is confirmed that a wide range of municipal solid waste is applicable for the materials of a new green CLSM.

DOI:

10.14359/18726


Document: 

SP221-33

Date: 

May 1, 2004

Author(s):

I Horiguchi and N. Saeki

Publication:

Symposium Papers

Volume:

221

Abstract:

This paper discusses the physical properties and leachate characteristics of a newly developed CLSM (Controlled Low Strength Materials) with a special type of cement as well as aggregate made from municipal solid waste. Eco-Cement, so-called in Japan, is the latest green cement made primarily from municipal refuse incineration ash and sewage sludge. Aggregate used in this paper was also made from the slag of municipal solid waste incinerator. High-volume off-specification fly ash was also used. This new type of green CLSM will he a promising sustainable material to reduce CO2 emissions. Test results showed an adequate strength development and reasonable flowability, especially when the mixture proportion is carefully designed. The leachate characteristics of this new CLSM are evaluated in this paper. Two types of standard tests showed acceptable leachate levels. From these tests results it was confirmed that a wide range of municipal solid waste may be applicable for the materials of the new green CLSM.

DOI:

10.14359/13276


Document: 

SP219-07

Date: 

March 1, 2004

Author(s):

T. R. Naik, R. N. Kraus, Y. Chun, and R. Siddique

Publication:

Symposium Papers

Volume:

219

Abstract:

Three series of flowable slurry mixtures were made, each series with three different sources of wood ash (W-1, W-2, and W-3). The series of mixtures were: low-strength (0.3 to 0.7 MPa), medium-strength (0.7 to 3.5 MPa), and high-strength (3.5 to 8 MPa) mixtures. Tests were performed for flow, air content, unit weight, bleeding, settlement, compressive strength, and water permeability. Wood ashes W-1 and W-3 caused expansive reactions in CLSM mixtures resulting in little or slight (average 1%) net shrinkage of CLSM. Wood ash W-2 caused either significant net swelling (15% for Mixture 2-L, and 21% for Mixture 2-M) or no shrinkage (Mixture 2-H) of CLSM. The 91-day compressive strength of low-strength, medium-strength, and high-strength slurry mixtures was in the ranges of 0.38 to 0.97 MPa, 1.59 to 5.28 MPa, and 4.00 to 8.62 MPa, respectively. Overall, the slurry mixtures showed an average increase in strength of 150% (range: 25% to 450%) between the ages of 28 days and 91 days. This was attributed to pozzolanic and cementitious reactions of wood ash. In general, water permeability of CLSM mixtures decreased with age.

DOI:

10.14359/13141


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