Iman Satyarno

Effects of Hybrid Polypropylene-Steel Fiber Addition on Some Hardened Properties of Lightweight Concrete with Pumice Breccia Aggregate

Lightweight concrete application in construction field is growing rapidly in these recent years due to its advantages over ordinary concrete. In this paper, pumice breccia which can be found abundantly in Indonesia is proposed to be utilized as the coarse aggregate. In spite of its benefits, lightweight concrete exhibits more brittle characteristics and lower tensile strength compared with normal concrete. On the other hand, fiber addition into concrete has become widely used to improve its tensile properties. Furthermore, the utilization of hybrid fiber in a suitable combination may potentially improve the mechanical properties of concrete. This paper experimentally examines the effects of hybrid polypropylene-steel fiber addition on some hardened properties of pumice breccia aggregate lightweight concrete. Five groups of test specimens with fixed volume fraction of polypropylene fiber combined with different amounts of steel fiber were added in concrete to investigate the density, compressive strength, modulus of elasticity, splitting tensile strength, and the modulus of rupture of the concrete mixtures. Test results indicate that hybrid fiber addition leads to significant improvement to the compressive strength, modulus of elasticity, splitting tensile strength, and the modulus of rupture of the pumice breccia lightweight aggregate concrete and meet the specification for structural purposes.

Seismic Performance of the King Cross Steel Profile in Interior Reinforced Concrete Beam-column Joint

The high amount of steel bar reinforcement in beam-column joints causes congestion problem. Here, king cross steel profile, as an alternative to shear reinforcement in the joint of reinforced concrete beam-column, is proposed. This is achieved by simplifying the assembly of king cross steel profile implants at beam-column joints as a shear reinforcement, which could be expected to replace the transversal reinforcement and enhance the joint shear strength. Two sets of interior beam-column joint subassemblies with stirrup reinforcement (SJ) and with king cross steel profile reinforcement (KCJ) as the shear reinforcement in the joint were studied. The experimental result concluded that the average peak load of SJ specimen was higher than that of KCJ. However, KCJ had good performance and contributed to the shear strength of the joint. The performance and contribution of KCJ can be seen from the load carrying capacity above 6.7% in the positive direction and below 24.91% in the negative direction compared with SJ. The pattern of the crack occurred showed a severe failure in the joint panel of KCJ. In this study, the width of the web was twice that of the flange, but in future studies, the width should be enlarged until it sufficiently fills the entire joint section and the width of the web is about six times of the flange. This web enlargement and flange reduction were performed by considering the area of a cross-section of the king cross profile and the requirement of shear capacity of the joint installed. It was done to increase the shear strength of the interior beam-column joint subassemblies with KCJ.

Full Height Rectangular Opening Castellated Steel Beam with Diagonal Stiffener

The full height rectangular opening castellated steel beam failed in Vierendeel mechanism. This makes the flexural capacity of castellated steel beam is lower than the original IWF section. This paper discusses analysis and test result of a full height rectangular opening castellated steel beam with diagonal stiffener. The diagonal stiffener used in this research has a purpose of preventing Vierendeel mechanism. This research used two specimens, a short span specimen to study shear behavior, and a long span specimen to study flexural behavior. Test results show that the long span specimen can avoid Vierendeel mechanism and increase the yield moment capacity by 1.6 times of the original IWF section. The failure of the short span specimen is a combination of shear failure and Vierendeel mechanism as in elastic condition, the diagonal stiffener, flange, and web post were worked and failed together. Based on the test result, truss analysis method can be used to calculate the flexural capacity of full height rectangular opening castellated steel beam with diagonal stiffener. Theoretical calculation of yield moment capacity of the long span specimen has 8.25% difference from the real yield moment capacity.

The Investigation on Setting Time and Strength of High Calcium Fly Ash Based Geopolymer

Fly ash based geopolymer normally gets the optimum strength by heat curing. This is considered as a hindrance to in-situ applications. Therefore, development of fly ash based geopolymer that suitable for ambient curing will widen the application to the concrete structure. This paper reports the results of an experimental study on setting time and development of compressive strength of class C fly ash based geopolymer paste produced in ambient curing condition. The main synthesis parameters such as water to the geopolymer solid ratio, alkali to cementitious ratio and molarity of NaOH were varied to understand their individual effect on setting time and the mechanical properties of the resulting geopolymer. The results suggested that generally the setting time increased with the NaOH molarity and the compressive strength of 59 MPa was obtained for geopolymer mixture cured at ambient temperature for 28 days with alkali to a cementitious ratio of 0.35 and 10 M NaOH. The results will be useful for developing the knowledge of the use of high calcium fly ash in producing geopolymer. This would be beneficial to the understanding the future applications of this material as new binding material.

ANALISIS DAYA DUKUNG BEBAN BALOK BETON BERTULANG TAMPANG T DENGAN PERKUATAN WIRE ROPE PADA DAERAH MOMEN NEGATIF MENGGUNAKAN PROGRAM RESPONSE-2000 DAN METODE PIAS

Abstrak: Response-2000 adalah suatu program yang dapat digunakan untuk menganalisis elemen beton bertulang akibat beban aksial, momen, geser, maupun kombinasi ketiganya sehingga respon beban-lendutan dapat diprediksi dan kekuatannya dapat diketahui. Makalah ini membahas perbandingan kapasitas daya dukung beban hasil pengujian balok bertulang tampang T yang diperkuat wire rope pada daerah momen negatif dengan analisis menggunakan Response-2000 dan metode pias. Metode pias dilakukan dengan cara membagi penampang menjadi sejumlah pias dengan ketebalan tertentu, kemudian menganalisis gaya-gaya yang bekerja sampai tercapai keseimbangan sehingga dapat ditentukan kapasitasnya. Analisis dilakukan terhadap 3 model balok tampang T, masing-masing 1 balok tanpa perkuatan, 1 balok diperkuat dengan 2 wire rope , dan 1 balok dipekuat dengan 4 wire rope . Jenis w ire rope yang digunakan adalah Independent Wire Rope Core (IWRC) dengan diameter 10 mm. Hasil analisis menunjukkan bahwa kurva hubungan beban-lendutan untuk semua balok berdasarkan analisis Response-2000 memiliki pola yang mendekati kurva hubungan beban-lendutan hasil pengujian. Namun demikian terdapat perbedaan pada kemiringan kurva di mana hal tersebut dapat disebabkan oleh adanya anggapan lekatan sempurna (perfect bond) pada program Response-2000 . Hal yang sama juga berlaku pada analisis metode pias. Daya dukung beban hasil Response-2000 menunjukkan rasio sebesar 1,05; 0,95; dan 0,89 terhadap hasil pengujian, masing-masing untuk balok tanpa perkuatan, balok diperkuat dengan 2 wire rope , dan balok dipekuat dengan 4 wire rope . Sedangkan kapasitas daya dukung beban hasil analisis metode pias menunjukkan rasio sebesar 1,05; 0,85; dan 0,76 terhadap hasil pengujian.

Evaluation of bolted connections in wood-plastic composites

Wood-plastic composite (WPC) is a relatively new material that consists of sawdust and plastic polymer using the extrusion process. Due to its attributes such as low water content, low maintenance, UV durability and being fungi and termite resistant. Nowadays, WPC has already been produced in Indonesia using sawdust from local wood such as Albizia (Paraserianthes falcataria) and Teak (Tectona grandis). Moreover preliminary studies about the physical and mechanical WPC board from Albizia sawdust and HDPE plastic have been carried out. Based on these studies, WPC has a high shear strength around 25–30 MPa higher than its original wood shear strength. This paper was a part of the research in evaluating WPC as potential sheathing in a shear wall system. Since still little is known about connection behavior in WPC using Indonesian local wood, this study evaluated the connection for both of these two types of wood-plastic composite. WPC board from Albizia sawdust will be projected as shear wall sheathing and WP...

Assessment of the 2004/2011 Earthquakes and Tsunamis in Indonesia and Japan: Lesson Learnt and Way Forward

Two great of around magnitude nine earthquakes those followed by big tsunamis have happened in Indonesia on December 24, 2004 known by Aceh earthquake and in Japan on March 11, 2011 known by Tohoku earthquake. Unlike Japan, Indonesia has hardly any preparedness in terms of people capacity and tsunami countermeasure structures technology at that time, therefore the number of infrastructure damages and casualties in Aceh tsunami is very high. However, the number of infrastructure damages and casualties due to Tohoku tsunami is still considered very high too. It was noted because the current preparedness and developed tsunami countermeasure structures including the natural ones like mangrove forest or coastal vegetations did not work well during the tsunami. The lesson learnt from these two tsunamis bring to a conclusion that further studies are still required to find better and more appropriate analysis, design and applications of countermeasures structures. Currently, there are still many areas around the world which are potential to be hit by tsunami like West Sumatra province in Indonesia.

Karakteristik pasca elastik dinding panel Styrofoam dengan tulangan horizontal akibat beban bolak-balik

Radin Inten roundabout is one of the important roundabout in the city of Bandar Lampun, which serves traffic from different directions, namely the traffic flow coming from Soekarno Hatta street and Z.A Pagar Alam street . The high volume of traffic that passes through the roundabout causing congestion or meeting a pretty solid vehicles from different directions. Roundabouts generally have a better survival rate than other types of intersection control . The purpose of this study was to determine the Level of Service ( LoS ), evaluate the performance of capacity and the feasibility of a roundabout. This research in a survey to obtain the facts - the facts of the symptoms that are known indicated and evaluated by doing examples in a manual the road capacity indonesia (MKJI) .The research value of the service level ( level of service ) tangle AB ( from Bakauheni to Tanjung Karang vice versa)is A with degree saturation of 0.4357, tangle BC (from Tanjung Karang to Kotabumi vice versa) is B with degree saturation of 0.6636 , while the fabric of CA (from Kotabumi to Bakauheni vice versa) is E with degree saturation of 0.9471. greatest congestion on the fabric of CA ( from North to East and vice versa ) due to the tangle of capacity can not serve existing traffic volumes . Keywords : levels of service , capacity of the roundabout , degree of saturation