In remote areas, most roads still use pavements that are very sensitive to climate change, especially those using clay pavements with high plasticity. In addition to the issue of cost, the difficulty of obtaining a proper source of material is another problem that has led to soaring prices for materials. In this regard, a study was conducted using local materials, namely zeolite as a stabilizing material added with waterglass as activating agent. The research began with samples of laterite soil and natural zeolite for XRD test (microstructure testing), and then testing for laterite soil’s index properties and engineering properties, namely Unconfined Compressive Strength and CBR value. The purpose of the test is to determine the correlation between the Unconfined Compressive Strength (UCS) and the soil bearing capacity (CBR) caused by adding zeolite as stabilizer material and waterglass as activator with increasing curing time. Laterite soils contain a brownish red iron oxide. The stabilizing material zeolite contains a crystalline mineral of alumina silicate SiO2. While waterglass composed of sodium meta silicate. Stabilization carried out by mixing 4%, 8%, 12%, 16%, and 20% of zeolite with addition of 2% waterglass, percentage was measured based on soil dry weight. Specimens were tested at curing time of 0, 7, 14, and 28 days. The test result shows increasing UCS and CBR values with increasing percentage of zeolite. At mix of 20% zeolite and 2% waterglass, the unconfined compressive strength reaches 23.54 kg/cm2 with CBR value 58% at 28 days of curing time.

In civil engineering, alternative materials showed rapid progress. Asphalt derived from Buton Island in Indonesia, also known as Asbuton, was located in the limestone bedrock. A large deposit of Asbuton could guarantee the supply of alternative construction materials. In that regard, Asbuton performance as an alternative material to several subjects needs to be analyzed. Therefore, this study was conducted to analyze Asbuton’s behavior as a filler in a floating column model as a soft soil improvement concept. Asbuton added to sand and gravel mixture as filler and waterglass as a binder. CBR samples were tested to acquire the optimum composition with varied curing days namely 0, 3, and 7 days, following ASTM D-1883, followed by a compressive column model test which was based on ASTM D-2166. Finally, the column applied to the soft soil layer to be tested in a loading test, and the results are then compared for each composition. The results showed that the granular material's composition including Asbuton, the waterglass content, and the curing period significantly affect the engineering properties of the artificial column. The results revealed that the granular column with Asbuton with the addition of waterglass could increase soil’s load capacity and reduce the settlement of soft soils. Doi: 10.28991/cej-2020-03091623 Full Text: PDF

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Granular Asbuton is a natural material that occurred millions of years ago. Asbuton is a huge natural asphalt reserve. The bitumen content of Asbuton is located in an inter-mineral cavity that is difficult to remove. If the layer is dug and then obtained Asbuton chunks, the Asbuton remains a unit between the bitumen and the mineral granules, even if it is crushed to a small size, the bitumen and minerals remain united. The proportion of bitumen and minerals in granular Asbuton has basic properties, such as grain size distribution, ability to drain water, compression properties when compressed, shear strength, carrying capacity, and innovation in reducing soil deformation and decline. This study aims to examine the characteristics of physical and mechanical properties, determine the amount of bearing capacity and, evaluate the deformation pattern of asphalt granular column foundation systems. Testing uses SNI and ASTM standards. Based on the results of testing the characteristics of Granular Asbuton obtained the value of qu max = 0.131 kg / cm3, in the conditions of the optimum water content of Proctor. The value of California Bearing Ratio (CBR-Unsoaked) was 1.79%. So from the results obtained, that the use of Granular Asbuton greatly affects the stability of the soil that will be used as the construction material because of this material functions as a binding material from other materials and can be given other activating materials that can increase the bearing capacity.

Self Compacting Concrete (SCC) is a plastic concrete that is easy to flow because of its own weight, fulfils all the desired concrete molds, and has the properties to compose itself. Very suitable applied to conventional concrete construction work that has a large specific gravity and compaction or vibration of concrete is needed. The purpose of compaction itself is to minimize the air trapped in fresh concrete, hence the concrete becomes homogeneous and voids do not occur. To increase the flexural strength of concrete, the addition of nylon fibers can be a solution. Nylon fiber is a material with polymer fibers that have fiber, film and plastic properties. The objective of this study is to evaluate the compressive strength and modulus of elasticity, tensile strength and flexural strength of concrete with the addition of nylon fiber. The percentage of nylon fiber addition of 0.5% and 1% of the weight of cement with a diameter of 0.35 mm and 0.65 mm and a length of 15 mm and 20 mm. With the addition of 1% nylon fiber, compressive strength increases 126% in variation of 0.65 mm diameter and L = 15 mm, tensile strength increases 56.27% in variations diameter of 0.65 mm and a fiber length of 20 mm and flexural strength increases 5.390% in variations a diameter 0.65 mm in the length of 20 mm. The diameter, length and volume of the addition of nylon fibers affect the concrete mechanical behavior. It is proven that the greater the diameter of the nylon and the percentage of the addition of nylon can increase the strength of concrete.

Abstract. Nowadays, castellated beam becomes popular in building structural as beam members. This is due to several advantages of castellated beam such as increased depth without any additional mass, passing the underfloor service ducts without changing of story elevation. However, the presence of holes can develop various local effects such as local buckling, lateral torsional buckling caused by compression force at the flange section of the steel beam. Many studies have investigated the failure mechanism of castellated beam and one technique which can prevent the beam fall into local failure is the use of reinforced concrete slab as lateral support on castellated beam, so called composite castellated beam. Besides of preventing the local failure of castellated beam, the concrete slab can increase the plasticity moment of the composite castellated beam section which can deliver into increasing the ultimate load of the beam. The aim of this numerical studies of composite castellated beam on certain loading condition (monotonic quasi-static loading). ABAQUS was used for finite element modelling purpose and compared with the experimental test for checking the reliability of the model. The result shows that the ultimate load of the composite castellated beam reached 6.24 times than the ultimate load of the solid I beam and 1.2 times compared the composite beam.

The innovative technique of a hybrid PVD timber pile as a vertical drain can be implemented to reinforce and improve soft soil. In this case, the acceleration of pore water dissipation could increase shear strength. The at soil of this study is to investigate the effectiveness of a hybrid eucalyptus pellita-PVD timber pile as a vertical drain. The test method applied is a laboratory model test, consisting of the installation of a hybrid pile on soft soil in a rectangular pattern with a spacing of 10 cm. Then by a static loading test was subjected on soft soil with an initial load of 10 kg and subsequent loads of 20 kg and 40 kg. Daily dial monitoring of the increase in pore water dissipation was performed during the preloading test. The results show that the hybrid pile could accelerate the process of pore water dissipation to the surface compared to using timber piles alone. The increase of soil density before and after the loading indicated that the hybrid piles enhanced the density by 3.9%, whereas the reinforcement using only timber pile just increased by 2.4%.

This study aims to determine the material composition and dimensions of X-block, develop a slope reinforcement model using X-block, evaluate the mechanical behavior of slopes that are reinforced with rock-bound by X-block, and analyze the performance of slope reinforcement using X-block. This research was conducted at Hasanuddin University's soil mechanics and civil engineering structure laboratory. The model scale test was employed in this study. The geometrical speciation of the test box is 150 cm in length, 60 cm in width, and 100 cm in height. The X-block model was produced using concrete with a FC of 25 MPa. The X-block was divided into two types: X-block type 1 and X-block type 2. Tensile strength testing is performed on the X-block. The slopes are made of clay soil and have a slope angle of 70 degrees. The loading test was conducted in three stages: without block, with X-block type 1, and with X-block type 2. The loading test uses a hydraulic pump equipped with a load cell and LVDT. The tensile strength of X-block type 1 is 2.56 MPa, whereas X-block type 2 has a tensile strength of 4.35 MPa. The development of the type X-block design, which is used as a retaining wall material, has shown that it can effectively withstand landslides on the slopes under consideration. The slope safety factor rose dramatically after being reinforced with type X-blocks, reaching 2.73 for both X-block type 1 and X-block type 2. Doi: 10.28991/CEJ-2022-08-03-014 Full Text: PDF