Influences of Different Waterproofing Agents on Water Resistance of Foamed Cement

2013 ◽  
Vol 662 ◽  
pp. 327-330 ◽  
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li
Keyword(s):  
Mechanical Strength ◽  
Water Absorption ◽  
Water Resistance ◽  
Mechanisms Of Action ◽  
Foam Structure ◽  
Rapid Hardening ◽  
Sulphoaluminate Cement ◽  
Softening Coefficient ◽  
The Impact ◽  
Chemical Foaming

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.

Effect and Action Mechanism of Superplasticizer on Foamed Cement

2014 ◽  
Vol 548-549 ◽  
pp. 1659-1662
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Water Resistance ◽  
Action Mechanism ◽  
Foam Structure ◽  
Softening Coefficient ◽  
Chemical Foaming

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.

Research on the Waterproof Properties of Lightweight Gypsum Materials

2014 ◽  
Vol 548-549 ◽  
pp. 1655-1658
Author(s):  
Lin Lin Li ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Stearic Acid ◽  
Water Absorption ◽  
Water Resistance ◽  
Hydrophobic Membrane ◽  
Sulphoaluminate Cement ◽  
Softening Coefficient ◽  
Humidity Environment ◽  
Scanning Electron ◽  
Surface Of Crystals

In this work, methods of introducing water-resistance to foamed gypsum were firstly adopted to investigate the influences of sulphoaluminate cement、redispersible latex powder and stearic acid emulsion on the mechanical strength、water absorption and softening coefficient. Scanning electron microscopy (SEM) was conducted to investigate microstructure of gypsum and phase composition of substances on plaster surface as well as the mechanisms. The result showed that sulphoaluminate cement reduced the water absorption of foamed gypsum, which decreases to 38.9% when dosage was 10%; Redispersible latex powder reduced the water absorption of foamed gypsum, which decreases to 35.6% when dosage was 5%; Stearic acid emulsion reduced the water absorption of foamed gypsum, which decreased to 30.1% when dosage was 3%; The combing use of sulphoaluminate cement、redispersible latex powder and stearic acid emulsion maked the water absorption decrease to 15.2% and the crystals became short and dense and a layer of organic hydrophobic membrane covered the surface of crystals and which makes gypsum less soluble and more suitable for use in humidity environment.

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
Keyword(s):  
Flexural Strength ◽  
Physical Properties ◽  
Water Absorption ◽  
Rice Straw ◽  
Water Resistance ◽  
National Standard ◽  
Hollow Block ◽  
Early Strength ◽  
Softening Coefficient ◽  
The Impact

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.

scholarly journals Low Water Absorption, High-Strength Polyamide 6 Composites Blended with Sustainable Bamboo-Based Biochar

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1367
Author(s):  
Shiliu Zhu ◽  
Yong Guo ◽  
Yuxia Chen ◽  
Shengquan Liu
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Water Absorption ◽  
High Strength ◽  
Polyamide 6 ◽  
Negative Effects ◽  
Plant Fibers ◽  
Maximum Decrease ◽  
Bamboo Fibers ◽  
The Impact

To promote the application of polyamide 6 (PA6) in wood–plastic composites, the negative effects associated with the thermal degradation of plant fibers must be overcome. In this study, waste bamboo fibers were subjected to pyrolysis and ball milling to afford nano bamboo-based biochar (BC), which was subsequently used as reinforcement to prepare PA6/BC nano composites by injection molding. In addition, the processing fluidity, water absorption, mechanical properties, and interface compatibility of PA6/BC composites were discussed. Results revealed that a BC content of less than 30 wt% is beneficial to improve the processing fluidity of the composites. With the increase in the BC content, the density of the PA6/BC composites gradually increased, while the water absorption of the PA6/BC composites gradually decreased, and the maximum decrease was 46%. Compared to that of pure PA6, the mechanical strength of PA6/BC composites was improved by the addition of BC, and the maximum tensile/flexural strength and modulus of PA6/BC composites increased by 41%/72% and 195%/244%, respectively. However, the impact strength decreased by 27%. After immersion treatment, the dimensional stability and mechanical strength of the composites decreased, while toughness improved. At a BC content of less than 40 wt%, BC particles exhibited good dispersibility and wettability in the PA6 matrix, and the rough surface and rich pore structure of BC rendered strong mechanical interlocking effects and good interface compatibility, thereby enhancing the mechanical properties of the composites.

Synthesis of Supplement Based on Calcium Hydrosilicate for Dry Mixes

2018 ◽  
Vol 876 ◽  
pp. 31-35
Author(s):  
Valentina Ivanovna Loganina ◽  
Irina Sergeevna Pyshkina ◽  
Georgiy Victorovich Martyashin
Keyword(s):  
Mechanical Strength ◽  
High Activity ◽  
Amorphous Silica ◽  
Frost Resistance ◽  
Water Resistance ◽  
Properties Of Coatings ◽  
X Ray ◽  
Calcium Hydrosilicates ◽  
The Impact ◽  
Calcium Hydrosilicate

Using of supplement based on calcium hydrosilicates as structuring supplement in dry mixes lime is proposed. It shows the impact of supplement synthesis mode on the structure formation of calcareous compositions. The efficiency of the using of modifying supplements of amorphous silica, such as diatomite, in the synthesis is shown. It has been established that in supplement of calcium hydrosilicates synthesized with diatomite a greater amount of calcium hydrosilicates, belonging to low-basic ones, are contained. X-ray analysis of samples based on synthesized supplements is presented. A high activity of synthesized calcium hydrosilicates had been established. It has been established that the injection of supplements of hydrosilicates accelerates the gain of mechanical strength. It is shown that the injection of supplements of hydrosilicates accelerates the increase of water resistance and frost resistance of coatings. The operational properties of coatings based on the developed dry mix with the addition of calcium hydrosilicates synthesized with diatomite are presented.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

scholarly journals X-ray Shielding, Mechanical, Physical, and Water Absorption Properties of Wood/PVC Composites Containing Bismuth Oxide

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  
Keyword(s):  
Impact Strength ◽  
Water Absorption ◽  
Attenuation Coefficient ◽  
Bismuth Oxide ◽  
Morphological Properties ◽  
Linear Attenuation Coefficient ◽  
X Rays ◽  
Equivalent Thickness ◽  
X Ray ◽  
The Impact

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.

scholarly journals Characteristics of Biodegradable Gelatin Methacrylate Hydrogel Designed to Improve Osteoinduction and Effect of Additional Binding of Tannic Acid on Hydrogel

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2535
Author(s):  
Ji-Bong Choi ◽  
Yu-Kyoung Kim ◽  
Seon-Mi Byeon ◽  
Jung-Eun Park ◽  
Tae-Sung Bae ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Water Absorption ◽  
Tannic Acid ◽  
Absorption Capacity ◽  
Animal Testing ◽  
High Concentration ◽  
Cell Compatibility ◽  
Property Evaluation ◽  
Bone Minerals ◽  
Cell Adhesion And Proliferation

In this study, a hydrogel using single and double crosslinking was prepared using GelMA, a natural polymer, and the effect was evaluated when the double crosslinked hydrogel and tannic acid were treated. The resulting hydrogel was subjected to physicochemical property evaluation, biocompatibility evaluation, and animal testing. The free radicals generated through APS/TEMED have a scaffold form with a porous structure in the hydrogel, and have a more stable structure through photo crosslinking. The double crosslinked hydrogel had improved mechanical strength and better results in cell compatibility tests than the single crosslinked group. Moreover, in the hydrogel transplanted into the femur of a rat, the double crosslinked group showed an osteoinductive response due to the attachment of bone minerals after 4 and 8 weeks, but the single crosslinked group did not show an osteoinductive response due to rapid degradation. Treatment with a high concentration of tannic acid showed significantly improved mechanical strength through H-bonding. However, cell adhesion and proliferation were limited compared to the untreated group due to the limitation of water absorption capacity, and no osteoinduction reaction was observed. As a result, it was confirmed that the treatment of high-concentration tannic acid significantly improved mechanical strength, but it was not a suitable method for improving bone induction due to the limitation of water absorption.

scholarly journals Microstructure and Durability Performance of Mortars with Volcanic Powder from Calbuco Volcano (Chile) after 4 Hardening Years

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1751
Author(s):  
Rosa María Tremiño ◽  
Teresa Real-Herraiz ◽  
Viviana Letelier ◽  
José Marcos Ortega
Keyword(s):  
Water Absorption ◽  
Thermal Analyses ◽  
Length Change ◽  
Cement Industry ◽  
Chloride Diffusion ◽  
Beneficial Effects ◽  
State Diffusion ◽  
Calbuco Volcano ◽  
Reference Specimens ◽  
The Impact

One of the most popular ways to lessen the impact of the cement industry on the environment consists of substituting clinker by additions. The service life required for real construction elements is generally long, so it would be interesting to obtain information about the effects of new additions after a hardening period of several years. Analyzed here are the effects of the incorporation of volcanic ashes, coming from Calbuco volcano’s last eruption (Chile), as clinker replacement, in the durability and pore structure of mortars, after approximately 4 hardening years (1500 days), in comparison with reference specimens without additions. The substitution percentages of clinker by volcanic powder studied were 10% and 20%. The microstructure was characterized with mercury intrusion porosimetry and impedance spectroscopy. In order to evaluate the pozzolanic activity of the volcanic powder after 1500 days, differential thermal analyses were performed. Water absorption after immersion, steady-state diffusion coefficient and length change were also studied. In accordance with the results obtained, the 10% and 20% substitution of clinker by volcanic powder from the Calbuco volcano showed beneficial effects in the mortars after 4 years, especially regarding the microstructure and chloride diffusion, without noticeable influence in their water absorption.

scholarly journals Functionalization of Enzymatically Treated Apple Pomace from Juice Production by Extrusion Processing

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 485
Author(s):  
Vera Schmid ◽  
Antje Trabert ◽  
Judith (Schäfer) Keller ◽  
Mirko Bunzel ◽  
Heike P. Karbstein ◽  
...  
Keyword(s):  
Water Absorption ◽  
Dietary Fiber ◽  
Water Solubility ◽  
Apple Pomace ◽  
Raw Material ◽  
Food Ingredients ◽  
Insoluble Dietary Fiber ◽  
Extrusion Processing ◽  
The Impact ◽  
Treated Apple

Food by-products can be used as natural and sustainable food ingredients. However, a modification is needed to improve the technofunctional properties according to the specific needs of designated applications. A lab-scale twin-screw extruder was used to process enzymatically treated apple pomace from commercial fruit juice production. To vary the range of the thermomechanical treatment, various screw speeds (200, 600, 1000 min−1), and screw configurations were applied to the raw material. Detailed chemical and functional analyses were performed to develop a comprehensive understanding of the impact of the extrusion processing on apple pomace composition and technofunctional properties as well as structures of individual polymers. Extrusion at moderate thermomechanical conditions increased the water absorption, swelling, and viscosity of the material. An increase in thermomechanical stress resulted in a higher water solubility index, but negatively affected the water absorption index, viscosity, and swelling. Scanning electron microscopy showed an extrusion-processing-related disruption of the cell wall. Dietary fiber analysis revealed an increase of soluble dietary fiber from 12.6 to 17.2 g/100 g dry matter at maximum thermo-mechanical treatment. Dietary fiber polysaccharide analysis demonstrated compositional changes, mainly in the insoluble dietary fiber fraction. In short, pectin polysaccharides seem to be susceptible to thermo-mechanical stress, especially arabinans as neutral side chains of rhamnogalacturonan I.

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