Effect of Rice Straw Amount Portion on Physical Properties of Adding Admixtures Hollow Block

2012 ◽  
Vol 450-451 ◽  
pp. 727-732 ◽  
Author(s):  
Jun Liu ◽  
Hong Hong Zhou ◽  
Bing Zhang

This study presents the impact of rice straw as additive material on physical properties of hollow block as compressive, flexural strength and water absorption, Softening coefficient. Through testing the hollow block physical properties, the of rice straw additive was studied. When the rice straw amount portion was 0~15%, with rice straw amount portion increased, compressive, flexural strength and water resistance effect of adding one kind of early strength agent and mixing Al2(SO4)3, CaCl2 early strength agent hollow block decreased gradually. When the rice straw amount portion was 10%, adding early strength agent Al2(SO4)3, CaCl2 ,the 28d compressive strength of hollow block was minimum, 3.5MPa; while mixing CaCl2, Al2(SO4)3 early strength agent, the hollow block softening coefficient was 0.76, water absorption rate was 3.9%, meet the requirements of national standard of common concrete hollow block. Through the experiment, the conclusion is mixing early strength agent Al2(SO4)3, CaCl2, Obviously superior to adding one kind of —early strength agent—Al2(SO4)3 or CaCl2 on the physical properties of hollow block.

2013 ◽  
Vol 662 ◽  
pp. 327-330 ◽  
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li

The rapid hardening sulphoaluminate cement was used to prepare foamed cement by the chemical foaming method. The impact of organic and inorganic waterproofing agent on the water absorption, mechanical strength and softening coefficient of foamed cement were studied. The results showed that adding waterproofing agent could improve its foam structure and reduce the water absorption, improve its mechanical strength and softening coefficient, thus improving its water resistance; Organic waterproof agents had a better performance than inorganic waterproof agents. The mechanisms of action of different waterproofing agent were explored.


2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.


2018 ◽  
Vol 8 (7) ◽  
pp. 1187 ◽  
Author(s):  
Yanbing Zong ◽  
Xuedong Zhang ◽  
Emile Mukiza ◽  
Xiaoxiong Xu ◽  
Fei Li

In this study, SiO2–Al2O3–CaO–MgO steel slag ceramics containing 5 wt % MgO were used for the preparation of ceramic bodies, with the replacement of 5–20 wt % quartz and feldspar by fly ash. The effect of the addition of fly ash on the sintering shrinkage, water absorption, sintering range, and flexural strength of the steel slag ceramic was studied. Furthermore, the crystalline phase transitions and microstructures of the sintered samples were investigated by XRD, Fourier transform infrared (FTIR), and SEM. The results showed that the addition of fly ash affected the crystalline phases of the sintered ceramic samples. The main crystal phases of the base steel slag ceramic sample without fly ash were quartz, diopside, and augite. With increasing fly ash content, the quartz diffraction peak decreased gradually, while the diffraction peak intensity of anorthite became stronger. The mechanical properties of the samples decreased with the increasing amount of fly ash. The addition of fly ash (0–20 wt %) affected the optimum sintering temperature (1130–1160 °C) and widened the sintering range. The maximum addition amount of fly ash should be 15 wt %, for which the optimum sintering temperature was 1145 °C, water absorption was 0.03%, and flexural strength was 43.37 MPa higher than the Chinese national standard GBT 4100-2015 requirements.


2013 ◽  
Vol 20 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Behzad Kord

AbstractThe effect of organomodified montmorillonite (OMMT) loading on the natural durability properties of polypropylene/wood flour composites exposed to brown-rot fungi (Coniophora puteana) was studied. To meet this objective, the blend composites were prepared through the melt mixing of polypropylene/wood flour at 50% weight ratios, with various amounts of OMMT (0, 3 and 6 per hundred compounds [phc]) in a hake internal mixer. The samples were then made by injection molding. The amount of coupling agent was fixed at 2 phc for all formulations. After specimen and culture medium preparation, the specimens were exposed to the purified fungus at 25°C and 75% relative humidity for 14 weeks. Identical specimens of the same composite, without being exposed to the fungus, were provided as the control specimens. After the discussed periods; weight loss, flexural strength, flexural modulus, hardness, water absorption, and thickness swelling of specimens were measured. Results indicated that OMMT had significant effects on the natural durability of the studied composite formulations. All mechanical properties were affected by the fungus, to a greater extent in the case of specimens without OMMT than the specimens with OMMT. Furthermore, the flexural strength and modulus increased with an increase of OMMT up to 3 phc and then decreased. However, the impact strength, water absorption and thickness swelling was decreased with increase of OMMT loading. Also, the lowest weight loss and the highest hardness were observed in the composite containing 6 phc organoclay. The morphology of the nanocomposites was examined by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Morphological findings revealed that intercalation came from the sample with 3 phc concentration of OMMT, which implies the formation of intercalation morphology and better dispersion than 6 phc.


Author(s):  
Youssef El Moussi ◽  
Laurent Clerc ◽  
Jean-Charles Benezet

The use of bio-based concretes performed with lignocellulosic aggregates constitute an interesting solution for reducing the energy consumption, greenhouse gas emissions and CO2 generated by the building sector. Indeed, bio-based materials could be used as an alternative of traditional materials such as expended polystyrene and mineral resources (e.g. glass and rock wools) for insulation. Furthermore, these bio-based concretes are known for their interesting insulation properties, indeed they allow to enhance thermal properties of buildings and enables moisture management which lead to design efficient building materials. For this purpose, bio-based concrete using rice straw as aggregate are studied in this present work. The impact of the characteristics of rice straw particle (particle size distribution, bulk density, and water absorption capacity, etc.) on both the mechanical and thermal properties of the bio-based concrete are investigated. Five formulations of rice straw concrete are examined, compared and then classified in terms of insulation properties and mechanical properties. The assessments are based on the measurement of density and thermal conductivity. The variation of compressive strength in function of the characteristics (mean particle length) of rice straw particle are assessed and discussed. The investigation covers also the porosity and density. Tests are also carried out on agricultural by-products with a view to highlight their chemical, physical and structural proprieties. The results show that the use of large particles with low water absorption capacity induce lighter concretes with the density between 339 and 505 kg/m3 and lead to a high compressive strength with a high mechanical deformability. Furthermore, it appears that an increase in the average length of rice straw particle lead to decrease of thermal conductivity of bio-based concretes. It varies from 0.062 to 0.085 W/(m.K).


2014 ◽  
Vol 548-549 ◽  
pp. 1659-1662
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li

The ordinary Portland cement was used to prepare foamed cement by the chemical foaming method. In this paper, the effect of superplasticizer on the water absorption and softening coefficient of foamed cement has been studied. The results show that the superplasticizer could improve foam structure, reduce the water absorption, and enhance the compressive strength and softening coefficient. The water resistance could be improved. When the dosage of superplasticizer was 0.3% (the quality of cement), compared with blank sample, the water absorption reduced 27.9%. When the softening coefficient was 0.68, softening coefficient increased 19.2%. The action mechanism of superplasticizer has been explored.


2007 ◽  
Vol 37 (5) ◽  
pp. 866-873 ◽  
Author(s):  
Jun Li Shi ◽  
Bernard Riedl ◽  
James Deng ◽  
Alain Cloutier ◽  
S. Y. Zhang

Mechanical and physical properties of medium-density fibreboard (MDF) panels made from black spruce ( Picea mariana (Mill.) BSP) top, middle, and butt logs were studied. The analysis of variance and analysis of covariance were both performed to examine the impact of log position in the tree on panel modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), linear expansion (LE), thickness swell (TS), and water absorption. Results indicate that MOE and IB strength of MDF panels made from top and middle logs were significantly superior to those of panels made from butt logs; however, there was no significant difference in MOE and IB between panels made from top and middle logs. Water absorptions of top and middle log panels were significantly lower than that of panels made from butt logs, and the difference in water absorption between panels made from top and middle logs was not significant. TS of top log panels was the smallest among the panels from the three log positions in the tree and was significantly different from those of middle and butt log panels. TS of butt log panels was the highest, which was significantly different from that of top and middle log panels. The differences in LE among the panels made from top, middle, and butt logs were not significant. The comparison of MOR of top, middle, and butt log panels was dependent on panel density because of the interactions among the three groups. Top and middle log panels showed superior properties, because the thinner cell walls of fibres from top and middle logs resulted in an increased compaction ratio compared with the butt log panels. Panel density affected both panel MOR and MOE considerably; however, its impact on IB, LE, TS, and water absorption was not significant in this study. The equations describing the linear relationships between MOR, MOE, and panel density were developed.


2013 ◽  
Vol 687 ◽  
pp. 219-228
Author(s):  
Eui Hwan Hwang ◽  
Jin Man Kim ◽  
Sun Gyu Park

For the recycling of rapid-cooled steel slag (RCSS), various specimens were prepared with the different replacement ratios of RCSS and the addition ratios of polymer binder. The physical properties of these specimens were then investigated by compressive strength test, flexural strength test, water absorption test, hot water resistance test, measurement of pore distribution and observation of micro-structures using scanning electron microscope(SEM). Results showed that compressive and flexural strength increased with the addition ratios of polymer binder and replacement ratios of RCSS, but those strengths decreased reversely when addition ratio of polymer binder and replacement ratio of RCSS were excessively high. By the hot water resistance test, the compressive strength and flexural strength decreased remarkably and total pore volume increased but bulk density decreased. SEM observation of structure before hot water resistance test revealed very compact infusion of structure but decomposition or thermal degradation appeared in polymer binder when observed after the hot water resistance test.


2017 ◽  
Vol 7 (02) ◽  
pp. 91
Author(s):  
Mungki Septian Romas ◽  
Ikhwan Pramuaji ◽  
Lies Indriati ◽  
Sonny Kurnia Wirawan

One of the raw materials furniture common in Indonesia is rattan. Because of the availability of local rattan is very limited so that it is necessary to find alternative raw materials that can be used to substitute the rattan. Paper ropes made from spinning paper, is one of alternative that can be utilized. Paper ropes making from various spinning papers have been studied. Some types of paper were used in this experiment. The spinning papers were characterized and treated to modify its surface properties especially to increase their water resistance. Paper ropes making were done by using the twisting machine and then the physical properties of paper ropes resulted were tested. The results showed that paper surface treatment increased tensile strength, and reduced water absorption and porosity of treated papers. The use of water barrier chemicals and adhesive are effective in increasing water resistance of paper surface. Decreased water absorption and porosity are  20% - 43% and 30% - 98%, respectively. Based on this result, paper ropes is potential to become an alternative raw material for furniture.  ABSTRAKSalah satu bahan baku furnitur umum di Indonesia adalah rotan. Karena ketersediaan rotan lokal sangat terbatas sehingga diperlukan untuk mencari bahan baku alternatif yang dapat digunakan untuk menggantikan rotan. Paper ropes yang terbuat dari spinning paper, merupakan salah satu alternatif yang dapat dimanfaatkan. Pembuatan paper ropes dari berbagai jenis spinning paper telah dipelajari pada penelitian ini. Beberapa jenis kertas digunakan dalam percobaan ini. Spinning paper dikarakterisasi dan diperlakukan khusus untuk memodifikasi sifat permukaannya terutama untuk meningkatkan ketahanan airnya. Pembuatan paper ropes dilakukan dengan menggunakan mesin pemilin dan pengujian sifat fisik paper ropes telah dilakukan. Hasil penelitian menunjukkan bahwa perlakuan khusus permukaan kertas meningkatkan kekuatan tarik, dan mengurangi penyerapan air dan porositas. Penggunaan bahan kimia water barrier dan adhesif cukup efektif dalam meningkatkan ketahanan air permukaan kertas.  Penurunan penyerapan air dan porositas masing-masing sebesar 20% - 43% dan 30% - 98%. Berdasarkan hasil ini, paper ropes memiliki potensi sebagai bahan bahan baku alternatif untuk furnitur.


2005 ◽  
Vol 6 (4) ◽  
pp. 93-100 ◽  
Author(s):  
Thomas R. Meng ◽  
Mark A. Latta

Abstract Resistance to impact fracture and high flexural strength are desirable properties of denture base acrylics. The purpose of this laboratory study was to determine the Izod impact strength, the flexural strength, the flexural modulus, and the yield distance for four premium denture resins. Bar specimens 86 x 11 x 3 mm of Lucitone 199, Fricke Hi-I, ProBase Hot, and Sledgehammer Maxipack were fabricated following the manufacturer's instructions for heat processing. The bars were surface finished using silicon carbide paper to 600 grit. Ten specimens from three lots of each material were made (n=30). Flexural strength, flexural modulus, and yield distance were determined by testing the specimens to failure using a three-point test fixture. Izod impact strength was determined using an Izod tester on un-notched specimens generated from the flexural test (n=60). Analysis of variance (ANOVA) and post-hoc Tukey's test were used for statistical comparison of each property. There were significant differences in the physical properties among the denture acrylics tested. Lucitone 199 demonstrated the highest impact strength, flexural strength, and yield distance (p<0.05). Lucitone 199 with an Izod impact strength of 5.5 ± 1.2 N·m, a flexural strength of 99.5 ± 4.5 MPa, and yield distance of 9.9 ± 0.76 mm exhibited statistically greater results than Fricki Hi-I, ProBase Hot, and Sledgehammer Maxipack. Fricki Hi- I with a yield distance of 7.3 ± 1.1 mm was statically greater than ProBase Hot and Sledgehammer Maxipack. Fricki Hi-I, ProBase Hot, and Sledgehammer Maxipack were statistically similar for the Izod impact strength and flexural strength tests performed. ProBase Hot and Sledgehammer Maxipack yielded statistically similar results for all tests performed. Flexural modulus had an inverse relationship to the impact strength, flexural strength, and yield distance. Citation Meng TR, Latta MA. Physical Properties of Four Acrylic Denture Base Resins. J Contemp Dent Pract 2005 November;(6)4:093-100.


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