Dimensional stability of engineered cementitious composites

Keskin, Süleyman Bahadır
Cementitious materials with strain-hardening property and high tensile ductility are promising materials on account of their mechanical and durability performances. These materials require special ingredients which make it costly to be used in conventional constructions. Hence, potential applications of Engineered Cementitious Composites (ECC) generally focus on layered systems or repairs which require the use of ECC together with another material. For it to be used especially as a repair material, it should have sufficient dimensional compatibility for preventing restrained shrinkage cracking. In this thesis, a strain-hardening fiberreinforced cementitious composite, named Engineered Cementitious Composites, was produced with local ingredients and their mechanical performance, dimensional stability properties were investigated. For investigating the effect of materials and mix proportions on mechanical properties, compressive strength, flexural strength with mid-span beam deflections and matrix fracture toughness tests were conducted. For determining the dimensional compatibility properties, autogenous, drying and restrained shrinkage tests were conducted along with tensile creep tests. As a result it was shown that, mechanical and dimensional stability properties are affected by the ingredients and mix proportions. It was shown that especially autogenous shrinkage of mixtures was relatively high which can cause early age cracking. In order to mitigate the adverse effect of autogenous shrinkage, the effect of pre-soaked expanded perlite aggregate replacement on mechanical, shrinkage and dimensional compatibility properties was investigated. As a result it was found out that autogenous shrinkage can be mitigated by the use of pre-soaked expanded perlite aggregate replacement.


Sonat, Emine Evren; Özerinç, Sezer; Department of Mechanical Engineering (2021-12-10)
Carbon fiber reinforced polymer (CFRP) composites are increasingly used in the aerospace industry due to their high specific strength compared to conventional metallic materials. However, a significant shortcoming of these composites is their increased susceptibility to damage. Structural repair is a common method to restore the load-carrying capacity of a damaged part when the damage size exceeds the pre-defined tolerances. Scarf and stepped bonded repair methods are the primary choice for cases that requi...
Impact damage sensing of multiscale composites through epoxy matrix containing carbon nanotubes
Arronche, Luciana; La Saponara, Valeria; Yesil, Sertan; Bayram, Göknur (2013-06-05)
Carbon nanotubes are used to provide increased electrical conductivity for polymer matrix materials, thus offering a method to monitor the structure's health. This work investigates the effect of impact damage on the electrical properties of multiscale composite samples, prepared with woven fiberglass reinforcement and epoxy resin modified with as-received multi-walled carbon nanotubes (MWCNTs). Moreover, this study addresses potential bias from manufacturing, and investigates the effectiveness of resistanc...
Comparative evaluation of steel mesh, steel fibre and high-performance polypropylene fibre reinforced shotcrete in panel test
Cengiz, O; Turanlı, Lutfullah (2004-08-01)
In this study, experimental investigations were performed on steel mesh (SM), steel fibre (SF) and high-performance polypropylene fibre (HPPF) reinforced shotcrete (HPPFRS) panels to evaluate performance characteristics such as toughness, flexural ductility, energy absorption and load capacity. The panel tests, in accordance with European specification for sprayed concrete (EFNARC), were made on 18 prismatic specimens having the same mix designs and were cured for 28 days but reinforced with various fibres....
Stress strain behaviour of structural lightweight concrete under confinement
Şenel, Mehmet Ali; Tasbahjı, Tayseer; Turanlı, Lutfullah; Sarıtaş, Afşin (null; 2015-12-11)
: In this study, stress-strain behavior of structural lightweight concrete is studied under unconfined and confined conditions. To this end, the use of naturally occurring perlite material as lightweight aggregate and cement replacement material is considered. Although there are several studies on the confinement effects on normal weight concrete, there is lack of data on the confinement behavior attained for structural lightweight concrete by spiral or stirrup reinforcement. In order to evaluate the perfor...
Experimental Investigation of Strength of Curved Beam by Thin Ply Non-Crimp Fabric Laminates
Arca, M. A.; PAPİLA, MELİH; Çöker, Demirkan (2016-06-09)
Resistance against delamination failure and through the thickness tensile properties of curved carbon fiber reinforced plastics composites are investigated experimentally by conducting the curved beam strength tests. Effect of novel material thin ply non crimp fabric (NCF) architecture on delamination resistance of carbon fiber reinforced composites are investigated and compare with that of standard UD layups. In order to determine through the thickness tensile properties of curved carbon fiber composites, ...
Citation Formats
S. B. Keskin, “Dimensional stability of engineered cementitious composites,” Ph.D. - Doctoral Program, Middle East Technical University, 2012.