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Oil palm clinker is formed by burning of oil palm kernel shell and fibrous materials in boiler furnace. The clinker is no longer a bio-material that has changed to inert material likes the crushed brick. Large quantities oil palm clinkers have become a waste and caused disposal problem. It requires extra costs for handling, transportation and finding out suitable the dumping site. Research has been conducted to explore the potentiality usage of oil palm clinker as fine and coarse lightweight aggregates at Universiti Pertanian Malaysia. Mixtures of oil palm clinker concretes were designed, prepared and tested. Mechanical properties of a good mixture of tensile strength, compressive strength, modulus of elasticity, creep and shrinkage were satisfied the standard engineering codes of practices. Oil palm clicker concrete was found lighter than conventional concrete, which usually weighs between 2240 and 2400 kg m-3. The means of compressive and tensile strengths were found 30.79 and 3.34 N mm-2 respectively. In addition, the mean of modulus of elasticity was 13.024 kNmm-2. Therefore, oil palm clinker aggregate and concrete are recommended to be used in lightweight reinforced concrete structures.

The effect of loss of ignition, specific gravity, fineness, specific surface area and soluble fly ash to compressive strength of geopolymer paste were studied. Six fly ashes from two different sources and different time of collection were evaluated. Sodium hydroxide and sodium silicate were used as alkali activator. Concentration of sodium hydroxide and mass ratio of sodium hydroxide to sodium silicate were fixed 14M and one respectively. The result indicated that the improvement in compressive strength of geopolymer paste was more influenced by fineness, specific surface area and soluble content of fly ash. Soluble content of fly ash greatly affected the compressive strength of geopolymer paste compare to the compressive strength of cement paste with 20% fly ash replacement.

Light weight buildings are required in Indonesia to reduce the risk due to the earthquakes. Therefore, the presence of lightweight materials are needed. Moreover, fly ash that is a waste of coal combustion process, has a basic ingredient of geopolymer binder. If the geopolymer binder is mixed with a foaming agent, it will be a lightweight geopolymer binder, in which it can be used as wall elements that have light weight. Furthermore, the utilization of fly ash will reduces the pollution due to the release of CO2 during production of Portland cement. Thus the use of fly ash results in environmental safety. This study investigate about fibrous lightweight geopolymer binder, in which the main materials used was fly ash with the alkali activator such as NaOH and Na2SiO3. Foaming agent was used to form micro-pores. Abaca fiber was used as a reinforcement to avoid cracks. Normal curing and steamed curing were utilized at temperature 60°C for 6 hours. Meanwhile, tests conducted were compressive strength, density and porosity. Steam curing method resulted an increase in strength and gives less density even though the same amount of pores was formed.

A research has been conducted to investigate the physico-mechanical and microstructure properties of geopolymers synthesised from metakaolin activated with sodium silicate solution. A wide range of physical and mechanical properties of geopolymers were studied such as bulk density, porosity, Vickers hardness, compressive strength, thermal expansion and thermal conductivity. It was found that these properties were directly related to geopolymers process variables such as Si:Al, Na:Al, Na2O:H2O, time and curing temperature. The structure of the resulting geopolymers was studied by using X-Ray diffraction (XRD) and the microstructure of geopolymers paste and the interfacial transition zone (ITZ) between the aggregate and the matrix of geopolymer were studied by using Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). The results gave a new insight into the composition-microstructure-property relationship of geopolymers and paving the way to the production of geopolymers with improved performance in a variety of applications.

The purpose of this research is to observe the strength of asphalt concrete using solidified coal waste or geopolymer. The use of geopolymer is known in enhancing concrete mixture strength. More detail in this study is to acquire the comparison rate of stability and flow of mixture using geopolymer and the one with ordinary filler. The stability and melting rate of this mixture will determine whether the use of geopolymer as a filler material in flexible pavement is applicable. In this research, the first stage is to find the initial mix design, which is not including the geopolymer filler. From this research, it is found that the use of geopolymer increases the stability in asphalt mixture but reduce the melting rate and increase the cavity in the mixture. Although the melting rate decreases and the voids increases, the result acquired still fulfills the minimum specification of asphalt concrete for the high level of traffic load.

Self-healing cement is a novel topic in concrete technology. Concrete is created to have its own ability to heal cracks. Crack closure is due to the material deposition of the gap so causing the crack closed. Materials used in this paper is mortar composition with ordinary portland cement replaced by calcium carbonate (CaCO3) and rice husk ash. There are three testing presented in this paper. The first is compressive test to determine the compression applied to mortar for initial cracks. The second is an ultrasonic pulse velocity (UPV) test to observe the depth of cracks and density of each composition. The third is macroscopic investigation to observe cracks wide in each mixture. The maximum compressive strength of 22.46 MPa shown by specimens made with 10% rice husk ash and 10% calcium carbonate cement. By the end of healing process, it reached 23.18 MPa. It was also shown that in crack depth decreased from 38 mm to 16 mm. From this analysis, it can be concluded that rice husk ash (RHA) and calcium carbonate (CaCO3) can be utilized as self-healing concrete materials.

Glass powder is known as a reactive material with silica content more than 72% and potentially considered as pozzolanic material. Moreover, it is known that binder containing silica fume 10-26% by weight increases the compressive strength of concrete. A low water to binder ratio is needed to increase the strength. In this paper, materials for making paste were analyzed for X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and reactivity. Composition of paste with the highest strength at 28 days was 93.26 MPa. Glass powders had higher reactivity compared to silica fume. Therefore, the recommended amount of glass powder to increase mechanical properties is 10 – 15% from cement weight and silica fume content are 40 – 60% from glass powder weight. A tendency of strength increasing after 28 days was found. In general, addition of silica fume to glass powder prolonged the initial setting causing the distance between initial and final setting time became closer.

With the advancement of technology and the economic crisis in Malaysia, has been promoting the development of infrastructure in the use of new structural materials but overall is unsatisfactory in terms of cost savings. One of the alternatives that can be used is to use fly ash as a cement replacement in manufacturing mortar. Replacement of cement with geopolymerization mortar can reduce manufacturing costs and could reduce global warming arising from the production of cement for the production of Portland cement for the release of CO2 into the atmosphere, where CO2 gas gives the largest contribution to global warming . The study will be focused on the effect of microwave curing with various durations and temperature to the mechanical and physical properties of fly ash based geopolymer mortar. For the conventional heating technique, heat is distributed in the specimen from the exterior to the interior leading to the non-uniform and long heating period to attain the required temperature. Application of microwave to the fresh concrete results in removal of water, collapse of capillary pore and densification of sample. Heat curing has been applied to construction materials especially for the precast concrete to improve the strength development process. This concrete attains sufficient strength in short curing time, so the molds can be reused, and the final products can be rapidly delivered to the site. The effect of curing temperature together with their aging days of the cured product will also be investigated. Mechanical properties of the product will be tested using compressive test, and density of the samples.

This paper presents the effects of chloride ions on OPC (Ordinary Portland Cement) concrete coated with fly ash-based geopolymer mortar. The coating was applied to protect concrete in coastal areas. The mortar was a mixture of fly ash and alkali activator with a mass ratio of 65:35. The alkali activator was a mixture of Na2SiO3 and NaOH 12M with a mass ratio of 2.5:1. The coating thickness varied at 2.5 cm, 4 cm, and 6 cm. All specimens were exposed to a marine area with seawater curing for 90 days. The mechanical properties of the specimen were determined by compressive strength. Chloride penetration was assessed for durability. A series of tests were carried out after 0, 30, 60, and 90 days of immersion. Compressive strength after a 90-day immersion increased by 34.16%, 39.81% and 31.38% for thickness 2.5 cm, 4 cm, and 6 cm respectively. Compressive strength with a thickness of 4 cm reached 52 MPa, which was the highest strength. The binding capacity of the chloride in geopolymer coatings was more than 80% and could reduce the free chloride content in concrete. Geopolymer mortar coating on OPC concrete showed good results in compressive strength and resistance to chloride attack from sea water. The recommended coating thickness for optimum results suitable for application is 4 cm.

Poorer reactivity of fly ash (FA) than Portland cement brings to the problems of low strength and setting time delays of very high-volume fly ash cement paste. This study combines precipitated-calcium carbonate (PCC) substitution and dilute-alkali fly ash treatment for overcoming those drawbacks. The strength was examined at 3-, 7-, 28- and 56-day. Scanning electron microscopy and Fourier-transform infrared spectroscopy were applied for characterisations. PCC substitution improved the strength and shortened the setting time; then additional dilute-alkali fly ash treatment results in better properties. Combination of PCC substitution and dilute-alkali treatment enhances cement hydration and FA pozzolanic reaction simultaneously.

This study discusses the effect of heating duration and curing age on compressive strength geopolymer paste made with medium calcium fly ash and potassium hydroxide solution (KOH). The hardening process was performed in an oven at a temperature of 100 ± 5°C in a variety of heating duration for 2, 4, and 6 hours to form a geopolymer paste with a potassium hydroxide concentration of 6 M. Flow testing on fresh paste indicatesd that all materials was bond properly without segregation. After the heating process in the oven, the spesimens were cured at room temperature until the age of 3, 7, and 28 days. The results of the compressive tests indicated that the heating duration and curing age were the key factors. Where there is no visible negative effect of the medium level CaO content in fly ash against compressive strength development of the hardened geopolymer paste.

International audience; This study discussed the mechanical properties of natural and metakaolin based geopolymer stabilized soil. The mechanical soil properties is an important soil properties that determine the soil strength parameter and its behaviour. It is proposed to do an assessment on 2 types of soil: natural (remolded) soil and metakaolin based geopolymer (MKG) stabilised soil of Bengawan Solo River Embankment soil. The soil sample are treated on oedometer test in order to know soil compressibility and permeability. The result shows that the implication of MKG for natural (remolded) soil only have an influence in reducing swelling. Also for the permeability, it is found that despite the high porosity (index high vacuum), its permeability is smaller than the permeability of other mixtures.

Jalan raya merupakan salah satu aset infrastruktur yang berperan dalam distribusi barang dan orang, perkembangan wilayah, ekonomi, sosial dan politik. Upaya pemeliharaan jalan dengan pengupasan material perkerasan di Provinsi Jawa Timur menghasilkan Reclaimed Asphalt Pavement (RAP) yang volumenya berkisar 50.000 m 3 /tahun. Upaya pemanfaatan Reclaimed Asphalt Pavement perlu dilakukan semaksimal mungkin sehingga menghasilkan campuran aspal beton yang memenuhi spesifikasi. Tujuan studi ini adalah memperoleh kinerja campuran aspal beton dengan penambahan Reclaimed Asphalt Pavement dan strategi pemanfaatan Reclaimed Asphalt Pavement. Metode yang digunakan adalah studi literatur dari peneliti terdahulu berbahan Reclaimed Asphalt Pavement dari jalan nasional di Provinsi Jawa Timur. Hasil yang diperoleh adalah kinerja teknis campuran dengan Reclaimed Asphalt Pavement memenuhi persyaratan Spesifikasi Bina Marga Tahun 2010 Revisi 3. Reclaimed Asphalt Pavement dapat digunakan pada lapisan AC-WC, AC-BC, AC- Base , dengan persentase penggunaan RAP sebesar 20-40%, RAP optimum sebesar 20-30%, kadar aspal dalam RAP sebesar 3,78-4,63%, VIM sebesar 4-4,825%, VMA sebesar 14,941-15,867%, VFB sebesar 65-87%, Stabilitas Marshall sebesar 830,482-2655,22 kg, flow sebesar 3,26-5,74 mm, Stabilitas Marshall Sisa sebesar 90,1-92,65 kg, VIM in PRD 2,525-5,09%. Strategi pemanfaatan Reclaimed Asphalt Pavement yaitu perlu menambahkan material lain yang baru atau material yang ramah lingkungan untuk digunakan sebagai material perkerasan jalan.

Fly ash is a by-product obtained from coal combustion process. Some of the utilization of fly ash is to produce geopolymer products which have high compressive strength, fire, chemical resistance. This paper proposes fly ash from unit 1-7 Suralaya Power Plant Indonesia. The aims of this study are to obtain characterization of fly ash and mechanical properties of geopolymer paste based on variations of the alkali activator ratio. The method was based on previous research and laboratory investigation. XRF and compressive strength were analysed in this study. Alkali activator was obtained from NaOH and Na2SiO3 mixture. The ratio of Na2SiO3 to NaOH was in the range of 0.5-2.5. Geopolymer paste was casted in acrylic cylinders with a diameter of 2 cm and a height of 4 cm. The curing was conducted at room temperature until the day for the compressive strength test at 28 days. The result showed that the fly ash is classified as F class. Increasing the alkali activator ratio influenced the strength. The best composition of geopolymer paste is made with NaOH 8M, and the mass ratio of Na2SiO3 to NaOH is 2.5. This composition produced compressive strength of 98.6 MPa.

Reclaimed Asphalt Pavement (RAP) is a dredging pavement material using Cold Milling Machine. The application of Reclaimed Asphalt Pavement is increased year by year. Due to the increasing application of RAP year by year which implicates environment condition, especially in damaging natural resources, the research on material used in RAP needs to be conducted, so RAP can be optimally utilized. To achieve optimal performance, data of RAP characteristics reviewed from microstructural analysis is necessary. The objective of this research is to obtain the characteristics of Reclaimed Asphalt Pavement. The method used was literary study based on previous research. Material tests used were XRF, SEM and FTIR. The object of study was RAP material taken from national road Waru Sidoarjo. The major compositions of Reclaimed Asphalt Pavement obtained were Kaolin, Lithium, Tetraborate, Dextrin. SEM graphics showed the morphological and surface texture of RAP. FTIR graphic presented the functional group of Reclaimed Asphalt Pavement showing O-H C-O acid in the peak of graphic. From XRD result, the major compounds of Reclaimed Asphalt Pavement obtained were Calcium, Sodium, Aluminum, Silicate.

This paper studies the effect of curing temperature and curing duration to the flood mud based geopolymer on compressive strength properties. Flood mud was used as a raw material for geopolymer and geopolymer samples were synthesized by using sodium silicate and sodium hydroxide 14M solution. These samples were cured at different temperature (100°C, 150°C, 200°C and 250°) for different curing duration (6h, 12h and 24h) respectively. Compressive strength tests were carried out at after 28 days. The compressive strength and SEM analysis of geopolymer products were evaluated. Result showed that the maximum compressive strength was 24 MPa at temperature of 150°C for 24 hours. With increasing ageing day, densification of geopolymer gel was observed.

Lightweight concrete is generally used particularly at high-rise buildings in order to reduce the risk of earthquake. It is common that lightweight concrete is made with less Portland Cement associated with pozzolanic material as a binder. In this paper, calcined-Sidoarjo mud was identified as pozzolanic material as cement substitution. The mud contains SiO2, Al2O3 and Fe2O3 and to be expected it has properties as a potential pozzolanic material. Paste and mortar as specimens made from mixtures of calcined-Sidoarjo mud, fly ash, lime, portland cement and natural sand. The specimens were then mixed with a commercial chemical foaming agent and Aluminum powder as aerating agents. The results showed that test paste specimens using chemical foam showed higher compressive strength and density than those of using aluminum powder. Lightweight paste made with chemical foam has compressive strength of 10.7 Mpa with density of 1133kg/m3. Moreover, the specimens of lightweight mortar had the compressive strength of 4.8 MPa, and the density of 1154.7kg/m3. Lightweight paste specimens using aluminum powder had a compressive strength of 2.8 Mpa with density of 1013kg/m3, while lightweight mortar specimens showed compressive strength of 2.4 MPa, and the density was 966kg/m3.

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.

This study is conducted to determine the effect of four variables on compressive strength of geopolymer concretes. These four variables are binder/aggregate, Alkalinene/fly ash, effect of superplasticizer (SP) addition and curing system. The compressive strength is important mechanical properties for construction material. Taguchi experimental design method is used to compile the concrete composition of geopolymer to achieve the maximum compressive strength. Specimens concrete used is a cylinder with 100 mm diameter and 200 mm height. Compressive strength test is performed at 28 day using SNI 03-6825-2002, Indonesian National Standard. This study concludes that the chloride environment has a beneficial effect on the compressive strength of the concrete. In addition, the Alkalinene/fly ash ratio and binder/aggregate give a significant effect on the compressive strength of geopolymer concretes.

Clay based geopolymer ceramic were produced through the geopolymerisation process by the alkali activation of kaolin with an activator solution which is mixture of sodium silicate and sodium hydroxide and undergoes heating at elevated temperature. The concentration of NaOH used in this study was in the range of 6 M-12 M. The ratio of kaolin to alkaline activator used is 1.0. Three different ratios of Na2SiO3/NaOH of 0.16, 0.24 and 0.32 were used to investigate the optimum flexural strength. The samples were cured at 80 °C for 24 hours and sintered at temperatures ranging from 900 °C-1200 °C. The optimum flexural strength of 86.833 MPa is obtained when the ratios of Na2SiO3/NaOH is 0.24 with the NaOH concentration of 12M at 1200 °C.

This paper presents an observation on fly ash quality in East Jawa, Indonesia. The ash samples were collected from 16 fly ashes produced by some Indonesian power plants. The samples are majority categorized as class F fly ashes with good pozzolanic characteristics according to the standard. The samples were examined for their physical, chemical and mechanical properties with compression test. The test was conducted by making some mortars and paste containing fly ash as cement replacement in accordance with three methods. The compressive strength results were compared with the control specimens made from ordinary Portland cement to obtain a strength activity index (SAI). The results showed that physical properties of fly ash influenced the mechanical properties of mortars more than those showed by chemical characterization.

This paper presents an experimental investigation on the improvement of geopolymer concrete properties through the use of polyvinyl alcohol (PVA) fibers mixed in the fresh concrete. For the purpose of obtaining the optimum mechanical properties, the volume fraction of PVA fibers was varied at 0%; 0.3%; 0.5%; ad 0.8%. All mixtures were cast by mixing fly ash, alkali activator, and aggregates. The activator used in this study was a combination of sodium silicate (Na 2 SiO 3 ) and sodium hydroxide (NaOH). The mechanical properties of geopolymer concrete were obtained from the results of compressive strength, splitting strength, uniaxial tensile strength, elastic modulus, and flexural strength. It is found that the variation of 0.8% PVA fibers resulted in the highest strength for overall test. The utilization of 0.8% PVA fibers also contributed to increasing the direct tensile up to 50%. However, it is noticed that the elastic modulus was more prone to decrease as the fiber content in the mixture increased.

This paper presents some results of experimental study of bond strength of plain bar embedded in geopolymer concrete. Fly ash class F was used as a raw material activated with alkali solutions. The combination of 8 Molar of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as alkali activators was examined in the mixture with ratio of 2.5 by weight. Nine cubical specimens with a size of 150 × 150 × 150 mm were prepared to measure bond strength and slip between reinforcement and concrete. The influential factors studied for the experimental investigation were the diameter of reinforcement bar, bond area, and concrete cover to diameter (c/d) of reinforcement. The result showed that the average bond strength decreased as the diameter of plain bar and bonded length were increased from 16 mm to 19 mm. However, the 12 mm showed the different result allegedly caused by the effect of bond area and the passive confined provided by the concrete. Based on several equations used to compare the bond strength, it i...

This paper presents more convenient deflection function that properly substitutes slow converging series function by Naiver for simply supported quadrilateral thin plate. The formulation of the deflection function was conducted by using variational approach. During formulation, Rayleigh-Ritz procedures was used and coordinate function that satisfies kinematic boundary condition and the minimum potential energy principle was developed. In addition to coordinate function, modification factor was applied to the main function for curve fitting purpose. To validate the current study, comparisons were done with Navier’s solution and finite element analysis. The results shown that the deviation for mid-point deflection of current study was very small, i.e. around 0.03%, from Navier’s solution. Furthermore, it has been investigated that finite element analysis also resulted closer result with current study.

Ammonia synthesis requires high pressure and high temperature process. Unfortunately, the capital intensive cost resulting low yield of ammonia by using recent catalyst which is iron oxide. Therefore, manganese zinc ferrite as a soft ferrite material will be introduced as a new nanocatalyst to enhance the ammonia yield. As a new nanocatalyst for ammonia production, study of comparasion two different concentration of MnZn Ferrite is very important. This paper will compare the yield of ammonia by using two different nanocatalyst which are Mn 0.4 Zn 0.6 Fe 2 O 4 and Mn 0.6 Zn 0.4 Fe 2 O 4 . Both were synthesized by sol-gel method and has been characterize by using FESEM (morphology), XRD (phase identification), EDX (elemental analysis) and TPR (oxide reduction). The ammonia was produce with and without magnetic field applied. The result shows that the ammonia yield is higher for Mn 0.4 Zn 0.6 Fe 2 O 4 nanocatalyst than Mn 0.6 Zn 0.4 Fe 2 O 4 by using magnetic field applied. 67.2% of yield has been achieved by using new nanocatalyst Mn 0.6 Zn 0.4 Fe 2 O 4 and magnetic field applied at ambient environment.

In this paper, we present the result of our study on the effect of steam curing to chloride ion penetration in geopolymer concrete. Class F fly ash was activated using sodium hydroxide (NaOH) and sodium silicate (Na 2 SiO 3 ). The concrete specimens were then steam-cured at 40°C, 60°C, 80°C and room temperature at 24 hours. The treatment was followed by wet curing for 28 days, and then followed by immersion of all specimens in salt water for the durations of 30, 60, and 90 days. Cylindrical specimens were then prepared for compressive strength, chloride ion penetration, pH, and porosity tests. A 16 mm-steel bar was fixed at the center of the specimen concrete blocks (specimen size: 10cm × 10cm × 15cm). Corrosion probability was determined by conducting Half Cell Potential test. Our result showed that increasing the curing temperature to 80°C induced chloride ion penetration into the concrete’s effective pores, despite improvements in compressive strength. We also found that chloride ingress on the geopolymer concrete increases commensurately with the increase of the curing temperature. The corrosion potential measurement of geopolymer concrete was higher than OPC concrete even if corrosion was not observed in reinforcing. Based on our result, we suggest that the corrosion categorization for geopolymer concretes needs to be adjusted.

This research has a purpose to confirm the resistance of geopolymer concrete towards high temperature. This high temperature becomes the issues in material structure defense due to the danger of fire. Therefore, this research is done on geopolymer paste, the main binding ingredient from fly ash as local industry waste material. The method that is used in order to achieve the objective is done experimentally in laboratory with the geopolymer testing paste constructed of type C fly ash. Fly ash was obtained from PT. Petrokimia Gresik. The activator alkali sodium hydroxide (NaOH) was designed 6, 10, and 14 Molar. The dimension of specimen shape was cylinder 2.5 cm × 5 cm. The maintenance of specimen done in a room temperature (27±3°C) until testing period 28 days and proceeded by test item burning process on 200°C and 600°C for 4 hours. The testing of the test item that is done includes the pressure strength test according to SNI-1974-1990. The result of this research shows that the pressure strength of geopolymer paste with NaOH 6, 10, and 14 molar at 200°C temperature has a better pressure strength than room temperature geopolymer paste.

In general, fly ash is often used as a binder in geopolymer mixture. In this paper, seven samples of fly ash were collected from five Indonesian power plants. The variation of fly ash may depend upon many factors. However, there is no standardization of fly ash used for geopolymer binder. This experiment was conducted to study and categorize fly ashes both by assessing their physical and chemical characters. All fly ashes were activated with alkali activator to prepare geopolymer paste. Ratio of fly ash to the alkali activator was kept constant at 65 : 35. Compression test was conducted at three, seven, 14, 21, 28, and 56 days to identify the strength development of each sample. The result revealed that the content of CaO in fly ash affected the setting time and early strength development. In three days paste with CaO content more than 20% gain 54% of its 28-day strength. It is caused by both hydration and polymerization reactions. A range of Si to Al ratio contributed to the strength.

This paper describes the effect of sintering temperature on the properties of metakaolin artificial lightweight aggregate (ALWA). Three types of sintering temperature applied in this research are 900°C, 1000°C and 1100°C, whereas ALWA without sintering treatment is used as data control. Properties of metakaolin ALWA investigated in this research are specific gravity, water absorption, physical appearance, porosity and aggregate impact value. Standard test used in this research is ASTM, AFNOR and British Standart. Based on the research results, it can be concluded that sintering temperature is greatly affect on the properties of metakaolin ALWA. Increased sintering temperatures can lead to decreased values of specific gravity, increased pore amount, increased aggregate impact value, increased water absorption values and change aggregate color to be more bright. Referring to the test results, sintering temperature not exceeding 900°C is recommended, as it provides good physical and mechanical properties to ...

This paper describes one of the varying factors influencing the mechanical properties of geopolymer concrete. Fly ash and volcanic material called trass was used as raw materials, while sodium Hydroxide (NaOH) and Sodium silicate (Na2SiO3) was applied as an alkali activator. Mechanical properties were assessed by compressive test, the concentration of NaOH used in this study was eight and ten Molars, and ratio of Na2SiO3to NaOH by mass was 0.5, 1, 1.5, 2, and 2.5. Test results indicated that the strength of geopolymer concrete and binder were hardly influenced by concentration of NaOH in solution and the activator ratio. Binder with activator ratio of 2.5 has the highest compressive strength both in 8M and 10M NaOH system. However, in concrete, there are a few difference, concretes made with 8M NaOH and activators ratio of 2 have the highest compressive strength. This result might due to the low workability of fresh geopolymer concrete. On the other hand, binder and concrete made with 10M NaOH, showed the highest compressive strength when they were made with the activator ratio of 2,5.

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

This paper presents the efforts of how to use the solid form of Sidoarjo mud as a base material of lightweight-geopolymer paste. The mud, which is called Lusi was mixed with a class F fly ash. Some experimental results have shown that mixing mud with fly ash and alkali was potential to become a binder in concrete, instead of Portland cement. Alkaline solutions used in the mixture were NaOH of 12 M and 14 M and Na2SiO3combined in the ratio of 1:2.5 by weight. Aluminum powder was applied as a foaming agent. It showed that the strength of paste made with mixing Sidoarjo mud and fly ash was influenced by mud content. The effect of chemical admixture and curing temperature was observed as well. A steam curing method at 60°C was applied to the paste for three and six hours. Test results showed that the compressive strength of the paste varied with the concentration of alkaline solution, mud content, admixture and curing temperature. The maximum strength of the lightweight paste at 21 days was 2.8 MPa with the density of 722 kg/m3.

This paper presents the experimental study on the control of the heat of hydration of mass concrete using the concrete bio-admixture, bioconc. The basic issue of mass concrete is thermal cracking, because of the heat of hydration of the cement content in mass concrete. This paper reports on the research results of using the concrete bio admixture, bioconc as a micro filler. To control the heat of hydration of mass concrete the cement content was reduced significantly up to 40 percent. The product is called bioconc low heat concrete. In order to control the researched object, it was compared with: pre-coolingmasscon and fly ash based low heat masscon. There were three parameters to be compared for asessing the product: hydration heat control effectiveness, cost of raw materials and the environmental impact. In this research, the concrete was made with fc’ 25 and the size of the mass concrete mock-up was 1000x1000x2500 mm3. Research result written in series of following data: the peak temperature, duration to reach peak temperature, thermal gap between core-edge off masscon and masscon raw material cost. The peak temperature at bioconc low heat concrete was 63.5 °C within 29.5 hours after pouring. It has thermal different at 19.5 °C. The cost of material was US$ 54.6 per cubic meter.

This paper presents the experimental study on the penetration of chloride ions in fly ash based-geopolymer concrete in the salt-water. To determine the corrosion possibility of reinforcement, lollipop-shape specimens with the size of 10x10x15 cm were prepared with the plain steel bar in the middle of concrete. The specimens were exposed to chloride ion penetration for 30-120 days. The mixtures were varied with alkali concentration of 8M-12M with the mass ratio of Na2SiO3 to NaOH was varied from 1.5 to 2.5. Specimens made with portland cement concrete was also prepared as the control. The best performance was showed by specimens made with 12M of NaOH. Due to ion exchange on the surface of geopolymer concrete, less chloride ion was found in geopolymer made with high alkali concentration. After 90 days, Portland cement concrete showed less performance while geopolymer concrete showed the strength increasing. High binding capacity due to soluble silicate content in geopolymer concrete was one of the reasons why geopolymer specimens are more resistant to chloride ion penetration.

Seismic performance of reinforced concrete frame Buildings which have been designed as Special Moment Resisting Frames in accordance to three Indonesian codes (SNI 1727-2013, SNI 1726-2012 andSNI 2847-2013) can be evaluated using nonlinear dynamic analysis. Criteria related to strength such as componentplastic rotation capacity, lateral displacement as well as criteria related to damage of elements in the structures were used to evaluate the seismic performance of the buildings. Assessment to the moment and curvature capacitiesof the cross sectionsof beams and columns were done using XTRACT. The global seismic performance of the structures depends on the seismic performance of components in the structures. In nonlinear model of the structures, the degrading strength of the components were modeled to take into account the gradual reduction of the contributed components to the resistance of the structures. PERFORM-3D is one of the software that can be used togenerate nonlinear model ofstructures. Seismic performance level of structures can be obtained from the results of the nonlinear dynamic analysis using PERFORM-3D. The Seismic performance level can be utilized for: (1) detecting any weaker part in the structures, and (2) evaluating theimproved design of the structuresfor enhancing the seismic performance of structures.

The previous study showed that asphalt concrete using filler geopolymer generate a higher value of stability. On the other hand, the value of flow and the porosity of the asphalt concrete were out of the specification range. This study examines the aggregate gradation analysis to improve the characteristics of mixed asphalt concrete geopolymer. The gradation of aggregate is variated into three following the available specification. The range of specification is then separated into three, those are aggregate gradation upper specifications, middle specification, and lower specification. Filler comes from geopolymer paste, composed of fly ash which is mixed with an activator. Activator is an 8 molar concentration of NaOH solution and Na₂SiO₃. The weight ratio of Na₂SiO₃ over the weight of NaOH solution was 1.5. Geopolymer paste waited until reached the age of 28 days, then pounded up to meet the requirement size of the sieve No. 200. The test of mixture characteristics was conducted to see the comparison of performance from different gradations. The test results showed that middle gradation generating characteristics of the mixture which is higher than upper gradation and lower gradation.

Beton mutu tinggi adalah beton yang kuat tekan tinggi sekitar 50 MPa – 100 MPa. Untuk meningkatkan kuat tekan, material pozollan seperti silica fume dan flyash biasanya digunakan untuk mengganti material beton Dalam laporan ini, beton mutu tinggi dengan silica fume sebagai pengganti semen dipelajari. Kadar silica fume yang digunakan adalah 0%, 5%, 7,5% dan 10%. Selain itu pengaruh dari mikrobakteri juga dipelajari. Faktor water per binder yang dipakai adalah 25% dari berat binder, dan untuk membuat workabilitynya bagus maka digunakan superplasticizer. Kadar superplasticizer yang digunakan dicari lewat trial pengujian di laboratorium. Pengujian yang dilakukan pada umur 1, 3, 7, 14, 21, 28 adalah uji tekan pasta, mortar dan beton, selain itu pada benda uji beton umur 28 hari akan dilakukan uji split beton dan uji porositas. Dari hasil penelitian didapatkan kuat tekan beton tertinggi pada umur 28 hari (B7,5M) adalah 69,71 MPa, sedangkan variasi silica fume yang paling optimum ada pada kadar 7,5%. Penambahan mikrobakteri tidak berpengaruh pada berat volume beton tetapi berpengaruh pada kuat tekan beton tersebut. Dengan penambahan mikrobakteri maka kuat tekan beton meningkat sebesar ± 30%. Sedangkan porositas total dan porositas tertutup yang terjadi pada beton semakin kecil, ini dibuktikan dengan hasil SEM terlihat bahwa bakteri mengisi area antara aggregat dan matrix beton.

Fly ash is applied widely in concrete. Therefore, the quality of fly ash plays a critical role in altering the compressive strength of concrete. As the fact, it is necessary to provide better insight on the characterization of fly ash based on their correlation index against the strength. This is regarded as the prior studies were merely focused on the relationship of fly ash percentage and compressive strength due to high demand and time-consuming. On the other hand, this paper offers more advanced analysis on the utilization of several methods to determine the effect of different fly ashes on the quality of mortar. In this study, 12 types of fly ash and six methods were involved. The differences between the methods consisted of how the samples were prepared and cured. In the mixture, 20% of fly ash and 80% of OPC (Ordinary Portland Cement) were used as a binder. The specimens were cured in two different methods (normal curing and steam curing). After 28-day of curing, specimens were tested under compression load to obtain the strength. The test results indicated that the method, where the fly ash was sieved in the preparation phase and was cured at a high temperature increased gradually, was found to be the fastest to analyze.

Specific microbial agents such as bacteria are often used in concrete to improve its performance. Some microbes act as self-healing agents to close cracks in concrete, and to increase concrete strength. This paper presents a study to observe the effects of microbe addition to two types of concrete mixtures the fly ash-based, as geopolymer paste, and portland cement paste containing fly ash. Furthermore, the investigation was conducted to compare the properties of each paste, such as its compressive strengths, specific gravities, porosity, microstructures, and XRay diffracting properties. The results indicate that microbial activities positively affected the properties of both, portland cement paste and geopolymer paste. The result reported here strongly suggests that fly ash can be used to produce a high quality, but environmental friendly construction material when it’s mixed together with useful microbes.

Alternative cementitious materials have been widely used because of the environmental issue of greenhouse gasses produced by portland cement production. A possible solution is the green concrete made from fly ash based-geopolymer paste. The natural differences of Indonesian coal ash lead to various chemical contents of fly ash. The chemical composition of alkali activated paste is also varied causing differences in the strength of the paste. Silica to alumina ratio is indicated as the greatest influencing factor to geopolymer strength. The bond among silica-alumina preserves a compact microstructure resulting in the strength. This paper proposes a Si-Al ratio between 1.5 and 2.0 by adding a synthetic aluminium substance from some sources. Using a natural aluminium substance from other fly ashes which contain excessive amounts of Al2O3was one of that efforts. The result indicated that the addition of a small amount of aluminium powder showed insignificant differences in geopolymer strength. The powder addition of up to 4% of fly ash decreased the strength by up to 60% of the original one. The methods of mixing are indicated as the trigger of lower strength because

Research on geopolymer concrete has seen a new light in the analyses and experiments for special topics in the field of their mechanical properties. Among the most important are studies of geopolymer concrete subjected to confinement and bond. Regarding the basic material behavior, research of material proportions formulations, mix design formulas and inventions towards the development of a high-performance geopolymer concrete, were conducted. The latest looked into the effects of molar activator concentrations to the 28 days compression strength, and the strength development as a function of concrete age for geopolymer concretes. The specimens were 150 by 300-millimeter cylinders tested in uniaxial compression. The molarity variations were set at 6, 8, and 10 molars. The geopolymer concrete samples were compared to conventional concrete specimens, having the exact same volumetric material proportions. The cement was replaced with fly ash, and the activator with water. The aggregate content was taken as a constant. The concrete strength as a function of molar increase followed a parabolic, convex pattern, suggesting that a maximum value exists. The strength development of all geopolymer concretes had a slower rate when compared to conventional concrete.

This paper investigates the effect of sintered fly ash lightweight aggregate as coarse aggregate substitution on the mechanical properties of concrete. The lightweight aggregate (LWA) was produced using the cold bonded method and then sintered at a temperature of 900°C. An alkaliactivated system was applied as a binding agent of the LWA. Fly ash was used as precursor while sodium hydroxide and sodium silicate were employed as alkali activators. Three variations of the LWA dosage were performed, which were 0%, 50%, and 100 % of the volume of coarse aggregate in the concrete mixture. The mechanical properties of the concrete investigated in this research are the compressive strength and split tensile strength. The result showed that the mechanical properties of the concrete slightly decrease along with the increased dosage of the LWA in the mixture. However, employing sintered fly ash the LWA is proven as an effective solution in reducing the concrete density without sacrificing its strength.

In this research, Class F fly ash and a mixture of alkaline activators and different amount of hooked steel fiber were used for preparing geopolymer concrete. In order to analyses the effect of hooked steel fiber on the geopolymer concrete, the analysis such as chemical composition of fly ash, workability of fresh geopolymer, water absorption, density, compressive strength of hardened geopolymer concrete have been carried out. Mixtures were prepared with fly ash to alkaline liquid ratio of 2.0 with hooked steel fibers were added to the mix with different amounts which are 1%, 3%, 5% and 7% by the weight of the concrete. Experimental results showed that the compressive strength of geopolymer concrete increases as the hooked steel fibers increases. The optimum compressive strength obtained was up to 87.83 MPa on the 14th day. The density of geopolymer concrete are in the range between 2466 kg/m3 to 2501 kg/m3. In addition, the workability value of geopolymer without hooked steel fibers is 100 mm while the workability value of geopolymer with hooked steel fibers are between 60 mm to 30 mm.

Quality of fly ash is varying widely in the field, it depends on the combustion process and the quality of the basic ingredients, namely coal. It will affect the physical and mechanical properties of the concrete mixtures used. This study used 12 samples of fly ash. The physical and chemical properties and finesse modulus were analyzed. The fly ash was mixed with OPC (Ordinary Portland Cement) with the proportion of 20% fly ash and 80% OPC. The specimens were form with mortar dimension of 5cm x 5 cm. The test was affected by the correlation of fly ash fineness modulus to compressive strength, correlation density of fly ash to compressive strength, and correlation of carbon content to the compressive strength.

Material Reclaimed Asphalt Pavement (RAP) and fly ash as waste that whose is abundant. So interesting to be researched. The research will be started by analyze of RAP, be obtained characteristics of aggregates and asphalt, then analyzed on an aggregate gradation; if aggregate gradation does not on gradation envelope will be required the addition of new aggregate. If asphalt does not match the requirements then also be required the addition of new asphalt. The next will be made the composition of mix- design for Asphalt Concrete - Binder Course (AC-BC) with variations addition of fly ash volume as filler. The aim of research to get variations addition of fly ash volume (4%,5% and 6%)

This study presents curing temperature influences to behaviors of geopolymer concrete. The concrete was fly ash based, with the ratio of fly ash to alkaline activator was 65%:35%. Ratio coarse aggregate to fine aggregate was 60%:40%, ratios Na 2 SiO 3 /NaOH were 1.5:2 and 2.5. A polycarboxilate superplasticizer with ratio was 2% to fly ash weight. Form of the test specimens were cylinder with diameter of 10 cm and 20 cm high. Steam curing conducted were at 40°C, 60°C and 80°C for 24 hours. The control specimens were treated at normal moist curing. Tests conducted were compressive strength, tensile strength, porosity and elasticity modulus. The results indicated that at the elevated temperature the compressive strength increases as well as tensile strength but decreases the closed porosity of specimens. The elasticity modulus had a similar tendency.

A damage case of light weight brick’s production approximately at 6-7% of total production was found daily in one industry in East Jawa, Indonesia. The physical damage of product always occured. This paper investigates some factors that affect the lost in laboratory analysis. The analysis includes the chemical analysis of raw materials, reactivity of pozzolanic materials, and observation of strength based upon the position of light-weight bricks during autoclaving process. In addition, fly ash is introduced as mineral additive as one of the alternatives to improve the product’s quality. It is also concluded that grinding the silica sands particles is the optimum way to improve the quality, but the adding class F of fly ash to five percent in mixture is the most effective solution. Furthermore, maintaining quality of raw materials, curing process, and maintaining the machine will either reduce the product damage that occurred during the fabrication process in industry.