Investigation of Properties of Engineered Cementitious Composites Incorporating High Volumes of Fly Ash and Metakaolin
[ N/A ]
Tarih
2012
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Amer Concrete Inst
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study was carried out to develop engineered cementitious composites (ECCs) incorporating binary blends of high volumes of fly ash (FA) and metakaolin (MK) for the purpose of achieving low drying shrinkage and high composite strength with adequate ductility and improved durability. ECC, an ultra-ductile cement-based composite reinforced with short random fibers, exhibits strain-hardening and multiple-cracking behavior in uniaxial tension and bending. Standard (M45) and high-volume FA ECC mixtures are typically produced by replacing portland cement (PC) with 55% and 70% of FA, respectively (FA-to-cement ratio of 1.2 and 2.2 by weight). In this study, the (FA + MK)/PC ratio was maintained at 1.2 and 2.2 and the FA/MK ratio was maintained at 4.5. Two replacement levels of MK with FA were adopted. The investigation used 10% and 12.5% MK by weight of total binder content, respectively. For the purposes of comparison, standard and high-volume FA ECCs were also studied. To determine the effect of binary blends of FA and MK on the properties of ECC, this study focused on the evaluation of free drying shrinkage, flexural and compressive strengths, porosity and water absorption (WA), sorptivity, and chloride-ion permeability. The experimental results showed that the drying shrinkage, porosity, absorption, sorptivity, and chloride-ion permeability properties were significantly reduced with the use of binary blends of FA and MK, while ECC's ultra-high ductility and strain-hardening properties were preserved at an adequate level.
Açıklama
Anahtar Kelimeler
drying shrinkage, durability, engineered cementitious composites, metakaolin
Kaynak
Aci Materials Journal
WoS Q Değeri
Q2
Scopus Q Değeri
Cilt
109
Sayı
5
