scholarly journals Mechanical Properties and Thermal Conductivity of Fly Ash-Based Geopolymer Foams with Polypropylene Fibers

2021 ◽  
Vol 11 (11) ◽  
pp. 4886
Author(s):  
Ni Komang Ayu Agustini ◽  
Andreas Triwiyono ◽  
Djoko Sulistyo ◽  
S Suyitno
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Fly Ash ◽  
Lightweight Concrete ◽  
Polypropylene Fibers ◽  
Gypsum Board ◽  
Foaming Agent ◽  
Alkaline Activator ◽  
Geopolymer Binder

This paper focuses on the effect of polypropylene (PP) fibers on the mechanical properties and thermal conductivity of fly ash-based geopolymer foams. Class C Fly ash (FA) was used as a binder material. A mixture of sodium silicate (SS) and sodium hydroxide (SH) was used as an alkaline activator of the geopolymer binder. The foams were prepared mechanically by mixing the foaming agent with distilled water at high pressure. The foams were added to the geopolymer admixture with volumes of 40% and 60%. A small dosage of PP was varied from 0%, 0.25%, and 0.50% by weight of fly ash (FA). The result showed that the strength of foamed geopolymer rises as the PP fiber content increases. The PP fiber was proven to increase the tensile strength of foamed geopolymer due to the ability of PP fiber to connect the crack and improve the tensile strength. The PP fiber amount in this study significantly affects the thermal conductivity of foamed geopolymer. However, the thermal conductivity in this study has the same properties as lightweight concrete and a little higher than gypsum board.

Lightweight Geopolymer Binder Base on Sidoarjo Mud

2014 ◽  
Vol 803 ◽  
pp. 148-159 ◽  
Author(s):  
Triwulan ◽  
J.J. Ekaputri ◽  
C. Huda
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Lightweight Concrete ◽  
Foaming Agent ◽  
High Rise ◽  
Pozzolanic Material ◽  
Alkaline Activator ◽  
Pozzolanic Materials ◽  
Geopolymer Binder

Sidoarjo mud has been a disaster for society and government of Indonesia, but this material contains of SiO2, Al2O3 and Fe2O3 so that significantly to be expected as a potential pozzolanic material. It would be very useful to take the advantages of the material. Moreover, lightweight concrete is widely applied especially at high-rise buildings in order to reduce the risk of earthquake. In general lightweight concrete is made with less Portland Cement associated with lime and pozzolanic materials as a binder. In this paper, calcined-Sidoarjo mud was introduced as pozzolanic material to create geopolymer paste. Geopolymer binders were made with a mixture of calcined-Sidoarjo mud, fly ash and alkaline activator. The specimens were then mixed with a commercial chemical foamed agent to get lightweight geopolymer binders. The results showed that the mixing with the ratio of fly ash : NaOH: Na2SiO3 were 33,3% : 33,3% : 9,52 % : 23,81% and superplasticizer was 2,5% of binder weight achieved the compressive strength of 55,6 MPa. With additional 1% of foaming agent, the compressive strength of lightweight geopolymer binder was 7.1 MPa

Fly Ash Based Lightweight Geopolymer Concrete Using Foaming Agent Technology

2014 ◽  
Vol 679 ◽  
pp. 20-24 ◽  
Author(s):  
Mohd Mustafa Al Bakri Abdullah ◽  
Zarina Yahya ◽  
Muhammad Faheem Mohd Tahir ◽  
Kamarudin Hussin ◽  
Mohammed Binhussain ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Room Temperature ◽  
Lightweight Concrete ◽  
Agent Technology ◽  
Alkali Activation ◽  
Geopolymer Concrete ◽  
Foaming Agent ◽  
Curing Conditions ◽  
Foam Generator

This paper presents the mechanical properties of a lightweight geopolymer concrete synthesized by the alkali-activation of a fly ash source (FA) produced by mixing a paste of geopolymer with foam produced by using NCT Foam Generator. Two curing conditions are used, curing at room temperature and curing in an oven with a constant temperature which is 60 oC. Bulk density showed that fly ash-based geopolymer lightweight concrete is light with the density of 1225 kg/m3 - 1667 kg/m3 with an acceptable compressive strength of 17.60 MPa for the density of 1667 kg/m3.

Effect of Alkaline Activator Ratio to Mechanical Properties of Geopolymer Concrete with Trass as Filler

2015 ◽  
Vol 754-755 ◽  
pp. 406-412 ◽  
Author(s):  
Puput Risdanareni ◽  
Januarti Jaya Ekaputri ◽  
Mohd Mustafa Al Bakri Abdullah
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Sodium Silicate ◽  
Setting Time ◽  
Geopolymer Concrete ◽  
Closed Porosity ◽  
Split Tensile Strength ◽  
Alkaline Activator ◽  
Test Result

This paper describes the effect of alkaline activator ratio (Na2SiO3/NaOH) to mechanical properties of geopolymer concrete. The mechanical properties of geopolymer concrete were assessed by setting time, split tensile strength and porosity. Fly ash was used as a cement substitute, and trass used as filler. While, Natrium hydroxide (NaOH) and Sodium Silicate (Na2SiO3) was applied as alkaline activator. In this study, NaOH concentration eight and ten molar with an alkaline activator ratio Na2SiO3/ NaOH by mass: 0.5, 1, 1.5, 2 and 2.5 were used. The test result showed that setting time, porosity and split tensile strength of geopolymer concrete were hardly influenced by NaOH concentration and the alkaline activator ratio. The alkaline activator ratio of Na2SiO3/NaOH has an optimum value at 2 and 2.5. Test result showed that the fastest setting time was 25 minute, the highest amount of closed porosity was 9.035 % and the highest split tensile strength was 2.86 MPa.

scholarly journals Compressive Strength and Thermal Conductivity of Fly Ash Geopolymer Concrete Incorporated with Lightweight Aggregate, Expanded Clay Aggregate and Foaming Agent

2019 ◽  
Vol 70 (11) ◽  
pp. 4021-4028
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Fly Ash ◽  
Lightweight Concrete ◽  
Sodium Hydroxide Solution ◽  
Density Ratio ◽  
Lightweight Aggregate ◽  
Alkali Activation ◽  
Geopolymer Concrete ◽  
Foaming Agent

This paper investigates the effect of incorporation of lightweight aggregate and foam in the preparation of lightweight aggregate geopolymer concrete (LWAGC) and lightweight aggregate foamed geopolymer concrete (LWAFGC). The geopolymer paste was formed by alkali activation of Class F fly ash in mixture of sodium silicate and sodium hydroxide solution. LWAGC was incorporated with expanded clay lightweight aggregate and river sand while hydrogen peroxide was added as foaming agent for LWAFGC. Results showed that LWAGC and LWAFGC achieved an excellent 28-day compressive strength of 60 MPa and 20 MPa, respectively. The bulk densities were 1815 kg/m3 for LWAGC and 1593 kg/m3 for LWAFGC. Even so, low thermal conductivity of 0.12 W/mK and 0.09 W/mK were reported. It was concluded that the joint effect of lightweight aggregate and foam produced geopolymer concrete with good mechanical strength while having excellent thermal insulating properties. The geopolymer concretes possessed high strength-to-density ratio to be regarded as lightweight high-performance structures. Keywords: Lightweight Concrete; Geopolymer; Expanded Clay Aggregate; Foam

scholarly journals An Investigation on Adding Polypropylene Fibers to Reinforce Lightweight Cement Composites (LWC)

2012 ◽  
Vol 7 (4) ◽  
pp. 155892501200700 ◽  
Author(s):  
Roohollah Bagherzadeh ◽  
Hamid Reza Pakravan ◽  
Abdol-Hossein Sadeghi ◽  
Masoud Latifi ◽  
Ali Akbar Merati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Fiber Length ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Splitting Tensile Strength ◽  
Hardened Concrete ◽  
Polypropylene Fibers ◽  
Cement Composites

The influence of polypropylene fibers has been studied in different proportioning and fiber length to improve the performance characteristics of the lightweight cement composites. Fibers used in two different lengths (6mm and 12mm) and fiber proportions (0.15% and 0.35%) by cement weight in the mixture design. Hardened concrete properties such as: 7- and 28-day compressive strength, splitting tensile strength, flexural strength, water absorption, and shrinkage were evaluated. Fiber addition was seen to enhance the physical and mechanical properties of lightweight concrete. Compared to unreinforced LWC, polypropylene (PP) reinforced LWC with fiber proportioning 0.35% and 12 mm fiber length, caused 30.1% increase in the flexural strength and 27% increase in the splitting tensile strength. Increased fiber availability in the LWC matrix, in addition to the ability of longer PP fibers to bridge on the micro cracks, are suggested as the reasons for the enhancement in mechanical properties.

scholarly journals Study of In Situ Foamed Fly Ash Geopolymer

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4059 ◽  
Author(s):  
Zijian Su ◽  
Wei Hou ◽  
Zengqing Sun ◽  
Wei Lv
Keyword(s):  
Thermal Conductivity ◽  
Fly Ash ◽  
Lightweight Concrete ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Sem Images ◽  
Foaming Agent ◽  
Aerated Concrete ◽  
Better Than

Foamed fly ash geopolymer was synthesized in this work to produce geopolymeric lightweight concrete (GLWC). Fly ash was activated by sodium silicate solution, and aluminum powder was employed as an in situ chemical foaming agent. The synthesized pastes were cured at 40 °C for 28 days, with bulk densities of resultant GLWCs ranging from 600 to 1600 kg/m3. The resulting mechanical properties, thermal conductivity, microstructure, and reaction product were fully characterized. Results show that GLWC had higher mechanical strength than commercial aerated concrete and developed 80–90% of its corresponding 28 days strength after curing for 7 days. For densities from 1200 to 600 kg/m3, the thermal conductivity diminished from 0.70 to 0.22 W/mK, which is much better than that of its counterpart, ordinary Portland cement (OPC). Scanning electron microscopy (SEM) images revealed decent matrices comprising geopolymeric gel and unreacted fly ash.

The Preparation of Fiber-Reinforced Foaming Desulfurization Gypsum

2013 ◽  
Vol 468 ◽  
pp. 28-31
Author(s):  
Lin Lin Li ◽  
Guo Zhong Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Thermal Insulation ◽  
Foaming Agent ◽  
Reinforcing Material ◽  
Different Content

Used the desulfurization gypsum, foaming agent and fly ash for molding thermal insulation foamed desulfurization gypsum, and studied the influence of different content of foaming agent on its density, mechanical properties and thermal conductivity. The result showed that when the content of foaming agent was 5%,the thermal conductivity was 0.052W/(m·K) reaching minimum, and the density of foamed desulfurization gypsum was 225Kg/m3 .To use glass fiber as reinforcing material for studying the effect of the vary content of glass fiber on strength of the material. The result showed that when the content of glass fiber was 1.5%, the flexural strength and compressive strength of the sample was increased 41.67%5.66% than the blank sample.

Effect of Cold Deformation and Annealing on Microstructure and Mechanical Properties of 5083 Aluminum Alloy Sheets

2018 ◽  
Vol 913 ◽  
pp. 49-54
Author(s):  
Jian Xin Wu ◽  
Chong Gao ◽  
Rui Yin Huang ◽  
Zhen Shan Liu ◽  
Pi Zhi Zhao
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Annealing Temperature ◽  
Cold Deformation ◽  
Rolling Process ◽  
Prolonged Annealing ◽  
5083 Aluminum Alloy ◽  
Research Hotspots

5083 aluminum alloy, due to moderate strength, good thermal conductivity and formability, is an ideal structural material for car production. Influence of cold rolling process on microstructures and mechanical properties of 5083 aluminum alloys is significant and research hotspots. In this paper, cold deformation and annealing processes on grains, tensile properties and anisotropies of 5083 alloy sheets were studied. Results showed that incomplete recrystallization occured on 5083 alloy sheets when annealing temperature was at 300°C. The degree of recrystallization increased slightly with the cold deformation raised from 30% to 50% and varied slightly with prolonged annealing time from 2h to 4h. Furthermore, fully recrystallization occurred on 5083 alloy sheets at the annealing temperature above 320°C. Tensile strength of 5083 alloy sheets reduced significantly when the annealing temperature was raised from 300°C to 320°C, while it varied slightly when the annealing temperature continued to rise to 380°C.

STUDYING THE EFFECT OF DIFFERENT ADDITIVES ON THE THERMAL CONDUCTIVITY AND MECHANICAL CHARACTERISTICS OF EPOXY-BASED COMPOSITE MATERIALS

2021 ◽  
Vol 25 (Special) ◽  
pp. 2-72-2-77
Author(s):  
Hassanein M. Nhoo ◽  
◽  
Raad. M. Fenjan ◽  
Ahmed A. Ayash ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Particle Size ◽  
Tensile Strength ◽  
Mechanical Characteristics ◽  
Volume Fraction ◽  
Pyrolysis Process ◽  
Volume Percent ◽  
Fair Comparison ◽  
Filler Level

The current paper deals with investigating the effect of two different fillers on the thermal and mechanical characteristics of epoxy-based composite. The filler used throughout the study are: charcoal and Pyrex, both of them are different in nature and have not been investigated thoroughly or even compared fairly in terms of their effect on polymer matrix. Further, they can be considered as a cheap filler, charcoal can be obtained from a simple pyrolysis process of plants (charcoal) and Pyrex waste can be collected easily. Both types are added to the selected matrix with volume percent ranged from 10 to 60 with increments of 10. To ensure a fair comparison, the particle size is fixed (is about 1.7 micrometer). The results showed that the epoxy thermal conductivity has enhanced by about two orders of magnitudes over the studied range of filler. In terms of mechanical properties, the charcoal improves the tensile strength about 84% at 60% volume fraction while the Pyrex effect is about 40% at the same filler level. On the contrast, the results of compressive strength do not show an appreciable improvement overall. It decreases by about 12% at 60% volume fraction of charcoal while increases about the same percent with Pyrex at the same filler level.

Preparation and Characterization of In Situ Nanocomposites of Graphene Nanosheets/Polyurethane

2019 ◽  
Vol 814 ◽  
pp. 90-95 ◽  
Author(s):  
Guang Lei Lv ◽  
Yuan Yuan Li ◽  
Chen Fei ◽  
Zhi Hao Shan ◽  
Jing Gan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Graphene Nanosheets ◽  
Graphene Sheets ◽  
Microstructural Properties ◽  
Wear Performance ◽  
Polyurethane Composites

Graphene nanosheets/polyurethane (GNS/PU) was prepared in situ by polymerization technique for the manufacture of PU safety shoes soles. The graphene nanosheets/polyurethane composites were characterized for their mechanical properties, thermal conductivity and abrasion resistance, and comparison is made with those of the neat polyurethane. The microstructural properties of GNS/PU were characterized by SEM. The results show that with the increase of the amount of graphene within the range of weight-percentages analyzed, the tensile strength of the composites gradually increases. The tensile strength of the GNS/PU composites increased to 64.14 MPa with 2 wt% GNS, compared with 55.1 MPa for neat PU. When the graphene sheets reached 2 wt%, the abrasion volume reached 71 mm3. Compared with the pure PU, the wear performance of GNS/PU composites was significantly improved.

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