The Influence Wall Thickness of Cement Hollow Spheres towards Compressive Properties of Cement Syntactic Foam

2013 ◽  
Vol 701 ◽  
pp. 291-295
Author(s):  
Norwanis Hasan ◽  
Syed Fuad Saiyid Hashim ◽  
Zulkifli Mohamad Ariff
Keyword(s):  
Compressive Strength ◽  
Wall Thickness ◽  
Hollow Spheres ◽  
Syntactic Foam ◽  
Cement Matrix ◽  
Compressive Properties ◽  
Failure Patterns ◽  
Different Types ◽  
Cellular Composite ◽  
The Difference

An innovative technique in producing cement syntactic foam (CSF) was proposed in this investigation. This cellular composite material basically consists of a cement matrix embedded with in-house developed cement hollow spheres (CHS). The produced foams incorporated with CHS having different wall thickness, were characterized for compressive strength and then compared with that of plain cement. It was observed that the CSFs were 37%-55% lighter than the plain cement but possessed compromised compressive strength. The comparative compressive properties of CSFs were also evaluated and reported. It was found that the CSF incorporated with thicker-coated CHS showed higher compressive strength compared to that of incorporated with thinner-coated CHS. The failure patterns within the test samples were also examined to determine the failure mechanism. These observations showed that both CSFs exhibited shearing type failure but exhibit different types of crack fractures due to the difference in CHS wall thickness.

Syntactic Foam Prepared with Glass Hollow Spheres of Designed Size and Wall Thickness Ratio

2014 ◽  
Vol 1061-1062 ◽  
pp. 129-132
Author(s):  
Zhuo Chen ◽  
Zhi Xiong Huang ◽  
Bing Yan Jiang
Keyword(s):  
Compressive Strength ◽  
Size Distribution ◽  
Wall Thickness ◽  
Hollow Spheres ◽  
Syntactic Foam ◽  
Thickness Ratio ◽  
Hollow Microspheres ◽  
Single Type ◽  
Compressive Properties ◽  
New Type

A new type of syntactic foam fabricated with four types of hollow microspheres (HGMs) were prepared and its compressive properties were tested following ASTM D 695-96 standard. The HGMs were designed to have specific size distribution and wall thickness. The compressive strength and modulus of the new syntactic foam were compared with those prepared with single type of HGMs. With same density, the new syntactic foam have better compressive properties.

Compressive Stress of Syntactic Foam: Effect of rNBR Particles Reinforced Epoxy Macrospheres (rNBR-EM)

2018 ◽  
Vol 280 ◽  
pp. 301-307
Author(s):  
Z. Zakaria ◽  
C.Y. Yao
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Compressive Stress ◽  
Energy Absorption ◽  
Wall Thickness ◽  
Syntactic Foam ◽  
Radius Ratio ◽  
Butadiene Rubber ◽  
Syntactic Foams ◽  
Compressive Properties

This research focuses on the effect of rejected nitrile butadiene rubber (rNBR) gloves particles reinforced epoxy macrospheres (EM) on the physical properties and compressive stress of syntactic foam. Adding rNBR particles on the surface of macrospheres can increase the energy absorption as a result of improving the compressive properties of syntactic foam. Three types of macrospheres have been produced for the fabrication of syntactic foam, namely EM without rNBR, 1-layer rNBR-EM and 2-layer rNBR-EM. The results showed that increased rNBR particles layer on macrospheres has increased the wall thickness, and reduced the radius ratio of macrospheres as well as increased the density of syntactic foams. The compressive strength and modulus of syntactic foam with 2-rNBR-EM increased compared to the syntactic foams of 1-rNBR-EM and EM without rNBR. In addition, the toughness of the 2-rNBR-EM increased compared to the syntactic foams of 1-rNBR-EM and EM without rNBR.

Fabrication and Properties of Syntactic Magnesium Foams

1998 ◽  
Vol 521 ◽  
Author(s):  
M. Hartmann ◽  
K. Reindel ◽  
R. F. Singer
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
Wall Thickness ◽  
Volume Fraction ◽  
Hollow Spheres ◽  
Three Dimensional ◽  
Syntactic Foam ◽  
Absorption Efficiency ◽  
Casting Technique ◽  
Energy Absorption Efficiency

ABSTRACTSyntactic magnesium foams which consist of thin-walled hollow alumina spheres embedded in a magnesium matrix were fabricated by infiltrating a three-dimensional array of hollow spheres with a magnesium melt by using a gas pressure-assisted casting technique.The resulting composite contains closed cells of homogeneous and isotropic morphology. The densities of the syntactic magnesium foams were between 1.0 and 1.4 g/cm3. The densities were controlled by variations in the bulk density of the hollow spheres with the volume fraction of spheres kept constant at approximately 63 %.Compressive deformation characteristics of the composites were evaluated with respect to the influence of matrix strength and sphere wall thickness on characteristic variables such as compressive strength, plateau stress and energy absorption efficiency. Differences in the strength of the magnesium-based matrix materials investigated (cp-Mg, AM20, AM50, AZ91) had little influence on the compressive strength of the syntactic foam. However, an increasing relative wall thickness of the hollow ceramic spheres led to a significant strength enhancement. In all cases the ratio between compressive and plateau strength rose with increasing composite strength resulting in decreasing energy absorption efficiency.

Compressive Strength of Organic Lightweight Aggregate Concrete

2011 ◽  
Vol 374-377 ◽  
pp. 1531-1536
Author(s):  
Cong Mi Cheng ◽  
Da Gen Su ◽  
Juan He ◽  
Chu Jie Jiao
Keyword(s):  
Compressive Strength ◽  
Relative Density ◽  
Lightweight Aggregate ◽  
Cement Matrix ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Slowing Down ◽  
Density Relationship ◽  
The Difference ◽  
Relationship Of

Organic lightweight aggregate concrete (OAC) is produced by replacing normal aggregate with organic aggregate in concrete or mortar either partially or fully, depending on the requirements of the strength and density. The study aims to investigate the compressive strength of OAC containing virgin EPS beads, recycled EPS granules and rubber granules with diameter 3-5 mm, and the influence of cement matrix on compressive strength of OAC. The results show that compressive strength of OAC decreases as organic aggregate content increases; furthermore, the decreasing rate of the strength is slowing down. The dimensionless compress strength-density relationship of EPS lightweight aggregate concrete (PAC) containing virgin EPS, recycled EPS and different cement matrix has uniform law. It can be modeled as σ*pl/σs=0.916(ρ*/ρs)3.04. The experimental compressive strength of ultra-lightweight EPS concrete with density lower than 900 kg/m3is much higher than the value calculated by Gibson formula. The larger the relative density is, the greater the difference between the two is. The dimensionless compressive strength-density relationship of rubcrete can be modeled as σ*pl/σs=0.956(ρ*/ρs)8.66. The compressive strength of rubcrete, compared with PAC, is more sensitive to the relative density.

The Incorporation of Nanoparticles into Conventional Glass-Ionomer Dental Restorative Cements

2015 ◽  
Vol 21 (2) ◽  
pp. 392-406 ◽  
Author(s):  
Elizabeta Gjorgievska ◽  
Gustaaf Van Tendeloo ◽  
John W. Nicholson ◽  
Nichola J. Coleman ◽  
Ian J. Slipper ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Zirconium Oxide ◽  
Cement Matrix ◽  
Glass Ionomer ◽  
Air Voids ◽  
Promising Strategy ◽  
Significant Difference ◽  
Different Types ◽  
The Matrix ◽  
Dental Restorative

AbstractConventional glass-ionomer cements (GICs) are popular restorative materials, but their use is limited by their relatively low mechanical strength. This paper reports an attempt to improve these materials by incorporation of 10 wt% of three different types of nanoparticles, aluminum oxide, zirconium oxide, and titanium dioxide, into two commercial GICs (ChemFil® Rock and EQUIA™ Fil). The results indicate that the nanoparticles readily dispersed into the cement matrix by hand mixing and reduced the porosity of set cements by filling the empty spaces between the glass particles. Both cements showed no significant difference in compressive strength with added alumina, and ChemFil® Rock also showed no significant difference with zirconia. By contrast, ChemFil® Rock showed significantly higher compressive strength with added titania, and EQUIA™ Fil showed significantly higher compressive strength with both zirconia and titania. Fewer air voids were observed in all nanoparticle-containing cements and this, in turn, reduced the development of cracks within the matrix of the cements. These changes in microstructure provide a likely reason for the observed increases in compressive strength, and overall the addition of nanoparticles appears to be a promising strategy for improving the physical properties of GICs.

Investigation of Composite Deflocculant Influence on the Properties of the Refractory Castable with Chamotte Aggregate

2014 ◽  
Vol 682 ◽  
pp. 256-260 ◽  
Author(s):  
Ina Pundienė ◽  
Irina Demidova-Buiziniene ◽  
A. Volochko
Keyword(s):  
Compressive Strength ◽  
Rheological Properties ◽  
Comparative Studies ◽  
Sodium Tripolyphosphate ◽  
Strength Properties ◽  
Cement Matrix ◽  
Hydration Products ◽  
Drying Process ◽  
Different Types ◽  
Compressive Strength Of Concrete

The influence of different types of deflocculants, PCE and sodium tripolyphosphate, on the rheological properties of the cement matrix was studied. It was established that composite deflocculant consisting of sodium tripolyphosphate and PCE Castament FS 20 provides the best rheological properties of the cement matrix and affects the composition of the hydration products. During the drying process of matrix with composite deflocculants mineral stratlingite additionally formed, which contributes to increment of strength properties. Comparative studies of refractory castable strength properties with chamotte aggregate showed that the compressive strength of concrete samples with composite deflocculants after hardening and after drying and burning is almost two times higher than the strength of samples with separate deflocculants.

Microstructure and Compressive Properties of Al/Al2O3 Syntactic Foams

2018 ◽  
Vol 933 ◽  
pp. 174-181 ◽  
Author(s):  
Ming Ming Su ◽  
Han Wang ◽  
Kai Yan Li ◽  
Hai Hao
Keyword(s):  
Hollow Spheres ◽  
Shear Bands ◽  
Syntactic Foam ◽  
Aluminum Matrix ◽  
Strain Curve ◽  
Stir Casting ◽  
Low Density ◽  
Syntactic Foams ◽  
Compressive Properties ◽  
Continuous Contact

Metal matrix syntactic foams with relativity low density (2.03 g/cm3) were prepared by stir casting method. The syntactic foam is comprised of alumina hollow spheres with a diameter range of 1.0-1.5 mm as reinforcement and ZL111 aluminum alloy as matrix. Calcium particles are used to increase the viscosity of the melt to ensure that low density hollow spheres are immersed in the melt. Microstructure characteristics and quasi-static compressive properties of syntactic foams were studied. The hollow spheres were uniformly distributed in the aluminum matrix, and the interface between them was in continuous contact. Compressive stress-strain curve exhibits three distinct stages of deformation: (i) the linear elastic stage; (ii) the plateau area; (iii) final densification stage. The compression strength and plateau stress are 85 MPa and 75 MPa, respectively. The main reasons for the sample failure are the collapse of hollow spheres and the formation of multiple shear bands.

Effect of Wall Thickness of Hollow Sphere on the Stress Distribution of Random Hollow Sphere Syntactic Foam

2014 ◽  
Vol 670-671 ◽  
pp. 630-633
Author(s):  
Zhuo Chen ◽  
Zhou Zhou ◽  
Bing Yan Jiang
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Wall Thickness ◽  
Hollow Sphere ◽  
Maximum Stress ◽  
Volume Fraction ◽  
Hollow Spheres ◽  
Syntactic Foam ◽  
Element Model ◽  
Spatial Arrangement

This paper addresses elastic analysis based on 3D finite element model for hollow sphere structures. In finite element models, which were analyzed under pressure of 1MPa, volume fraction of hollow spheres is kept at 30%, and hollow spheres are randomly located in the matrix. Five types of hollow sphere are used to form the model. All the types of hollow spheres have 60μm particle sizes, but different wall thicknesses. A comparison in stress distribution between the hollow sphere and matrix is made, which shows that in composites containing thin-walled hollow particles the maximum stress is located in the inner surface of particle wall, whereas increasing the wall thickness of hollow spheres results in getting some part of matrix around hollow spheres involved in energy absorption. Moreover, the location of the maximum stress in matrix related closely to the spatial arrangement of the particles. The study provides an insight into the micro structural performance of syntactic foam under load.

scholarly journals Effects of Polypropylene Fibre and Strain Rate on Dynamic Compressive Behaviour of Concrete

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1797 ◽  
Author(s):  
Meng Chen ◽  
Chenhui Ren ◽  
Yangbo Liu ◽  
Yubo Yang ◽  
Erlei Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Split Hopkinson Pressure Bar ◽  
Absorption Capacity ◽  
Fibre Content ◽  
Hopkinson Pressure Bar ◽  
Compressive Properties ◽  
Failure Patterns ◽  
Compressive Behaviour

This paper presents an experimental study on the dynamic compressive behaviour of polypropylene (PP) fibre reinforced concrete under various strain rates using split Hopkinson pressure bar (SHPB) equipment. The effects of PP fibre content and strain rate on the dynamic compressive stress-strain relationship and failure patterns were estimated. The results indicated that the addition of PP fibre enhanced the dynamic compressive properties of concrete mixtures although it resulted in a significant reduction in workability and a slight decrease in static compressive strength. Considering the workability, static compressive strength and dynamic compressive behaviour, the optimal PP fibre content was found to be 0.9 kg/m3 as the mixture exhibited the highest increase in dynamic compressive strength of 5.6%, 40.3% in fracture energy absorption and 11.1% in total energy absorption; further, it showed the least reduction (only 5.8%) in static compressive strength among all mixtures compared to the reference mixture without fibre. For all mixtures, the dynamic compressive properties, energy absorption capacity, strain at peak stress, ultimate strain and dynamic increase factor (DIF) were significantly influenced by strain rate, i.e., strain rate effect. When the strain rate was relatively low, PP fibres were effective in controlling the cracking, and the dynamic compressive properties of PP fibre reinforced mixtures were improved accordingly.

scholarly journals Assessment of the compressive strength of lime mortar in the joints of brick walls - case study

2018 ◽  
Vol 163 ◽  
pp. 02006 ◽  
Author(s):  
Dawid Łątka ◽  
Piotr Matysek
Keyword(s):  
Compressive Strength ◽  
Wall Thickness ◽  
Test Results ◽  
Lime Mortar ◽  
Punch Test ◽  
The Difference

The paper presents the test results of lime mortar compressive strength in the joints of brick walls. The tests were carried out with the Double Punch Test (DPT) method and with the use of an impact penetrometer (penetrometric test PT) on original samples taken from the structure of a building erected in the 1880s. The obtained results have shown that the predictions of the mortar compressive strength using both methods were very consistent (the difference 6%). The penetrometric method also made it possible to assess the homogeneity of the mortar in the direction of the wall thickness.

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