Effect of Calcium Carbonate Whisker on Impact Toughness of Precast Concrete

Cementitious composites are porous material having complex structure system consist of hydration products, un-hydrated cement particles and pore solutions of various scales. Calcium carbonate whisker is a new type of low cost micro-scale filler fiber gaining popularity in the field of construction materials. However, addition of whisker has effect on physical, mechanical and microstructural characteristics of cementitious composites. Also, the low production cost of whisker will make the use of micro fiber more extensive in large scale construction projects. In this study, the effect of calcium carbonate whisker on physical, mechanical and microstructural properties of cementitious composites with different fiber contents are investigated. The fluidity, drying shrinkage, pore structure, impact resistance, compressive, flexural and splitting-tensile strength of whisker-mortar are considered. The scanning electron microscopy analysis is also performed to examine the microstructural and toughening mechanism of whisker reinforced composites. It was concluded that the addition of calcium carbonate whisker up to 10 % improves the physical and mechanical properties of cementitious composites and is suggested to be the optimize content. The calcium carbonate whisker also resists the crack propagation at micro scale and showed the toughening mechanism with better interfacial properties between whisker and matrix.

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Characterization of mechanical behavior and mechanism of calcium carbonate whisker-reinforced cement mortar

Construction and Building Materials ◽

10.1016/j.conbuildmat.2014.05.059 ◽

2014 ◽

Vol 66 ◽

pp. 89-97 ◽

Cited By ~ 40

Author(s):

Mingli Cao ◽

Cong Zhang ◽

Haifeng Lv ◽

Ling Xu

Keyword(s):

Calcium Carbonate ◽

Mechanical Behavior ◽

Cement Mortar ◽

Reinforced Cement ◽

Calcium Carbonate Whisker

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Progress of Bio-Calcium Carbonate Waste Eggshell and Seashell Fillers in Polymer Composites: A Review

Journal of Composites Science ◽

10.3390/jcs4020070 ◽

2020 ◽

Vol 4 (2) ◽

pp. 70 ◽

Cited By ~ 2

Author(s):

Stephen Owuamanam ◽

Duncan Cree

Keyword(s):

Tensile Strength ◽

Calcium Carbonate ◽

Environmental Impact ◽

Impact Toughness ◽

Flexural Strength ◽

Polymer Composites ◽

Polymer Materials ◽

Future Research ◽

Carbonate Mineral ◽

Thermoset Polymer

Disposal of massive amounts of eggshells and seashells from processing industries is a challenge. In recent years, there has been a focus to reuse these waste resources in the production of new thermoplastic and thermoset polymer materials. This paper reviews eggshell and seashell production by country and provides a perspective on the quantity of bio-calcium carbonate that could be produced annually from these wastes. The achievements obtained from the addition of recycled bio-calcium carbonate fillers (uncoated/unmodified) in polymer composites with a focus on tensile strength, flexural strength and impact toughness are discussed. To improve compatibility between calcium carbonate (mineral and bio-based) fillers and polymers, studies on surface modifiers are reviewed. Knowledge gaps and future research and development thoughts are outlined. Developing novel and innovative composites for this waste material could bring additional revenue to egg and seafood processors and at the same time reduce any environmental impact.

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Chitosan Derivatives/Calcium Carbonate Composite Capsules Prepared by the Layer-by-Layer Deposition Method

Journal of Nanomaterials ◽

10.1155/2008/185632 ◽

2008 ◽

Vol 2008 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Takashi Sasaki ◽

Misato Shimizu ◽

Yusong Wu ◽

Kensuke Sakurai

Keyword(s):

Calcium Carbonate ◽

Shell Thickness ◽

Layer By Layer ◽

Deposition Mechanism ◽

Molecular Weights ◽

The Core ◽

Layer Deposition ◽

Calcium Carbonate Whisker ◽

Core Rod ◽

Hollow Capsule

Core/shell capsules composed of calcium carbonate whisker core (rod-like shape) and chitosan/chitosansulfate shell were prepared by the layer-by-layer deposition technique. Two chitosan samples of different molecular weights (Mw=9.7×104and1.09×106g·mol-1) were used as original materials. Hollow capsules were also obtained by dissolution of the core in hydrochloric acid. Electron microscopy revealed that the surface of the shell is rather ragged associated with some agglomerates. The shell thicknesslobeys a linear relation with respect to the number of deposited layersmasl=md+a(a>0). The values ofd(thickness per layer) were 4.0 and 1.0 nm for the higher and lowerMwchitosan materials, respectively, both of which are greater than the thickness of the monolayer. The results suggest that the feature of the deposition does not obey an ideal homogeneous monolayer-by-monolayer deposition mechanism. Shell crosslinked capsules were also prepared via photodimerization reaction of cinnamoyl groups after a deposition of cinnamoyl chitosan to the calcium carbonate whisker core. The degree of crosslink was not enough to stabilize the shell structure, and hollow capsule was not obtained.

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