Stability is a measure of the strength of an asphalt mixture in resisting deformation due to loading. If a road construction structure cannot withstand the existing load, it will result in road damage that endangers road users. This study aims to improve the stability of the asphalt concrete mixture with the use of crumb rubber. Crumb rubber is used because it has good resistance and elasticity. The research was conducted experimentally by making test objects in the laboratory. In this study, five variations crumb rubber (2%, 4%, 6%, 8%, and 10% of the weight asphalt mixture) were carried out with the size of the powder retained on a 40 sieve. Marshall test and analysis of volumetric was carried out to determine the characteristics of the asphalt-concrete mixture. The results showed that the highest Marshall stability was obtained at 10% crumb rubber with a stability value of 1422 kg. The use of rubber powder can significantly increase the strength and quality of the asphalt-concrete mixture. Thus, crumb rubber can be used, and this percentage can be used as a reference in the manufacture of asphalt-concrete mixtures in order to obtain good road pavement quality.

Reinforced concrete columns are structural members used to carry compressive loads. Column planning is important, considering that the column is the main structural element supporting the loads on a building. Column planning is generally used in moment and axial force interaction diagrams for a certain reinforcement ratio. Although there is currently much software available, Interaction diagrams made in this paper can be said to be a simple way of column planning. The method used in this paper is a numerical calculation method with the help of Ms Excel. This paper aims to optimize the planning of reinforced concrete columns using Mn and Pn interaction diagrams. Furthermore, the optimization results of the column planning interaction diagram have been obtained. A reinforcement ratio of 2% is a better result to apply. Keywords: column, interaction diagram, reinforcement ratio.

Evaluation of structural performance in Indonesia has been carried out for several high-rise buildings as part of the owner's demands for safety guarantees to determine the level of security that the building has. A simple but accurate nonlinear analysis is needed to determine the structure's performance under earthquake loads. The capacity spectrum method (pushover analysis) documented in ATC 40 is a form of equivalent linearization based on two basic assumptions: secant period and equivalent damping. The performance point estimates where the capacity of the structure can withstand a given (demand) load; In terms of performance, the level of damage to the structure category based on lateral displacement can be seen. It is simulated that an earthquake will shake the Klaten DPRD building with a magnitude of 7.0 and 20 km from the epicenter. The amount of PGA(g) will be calculated based on the equation of Cornell et al. Building structure modeling was carried out with the help of ETABS v9.7.4.

Pembuatan konstruksi jalan di Indonesia banyak menggunakan aspal beton.Penelitian ini bertujuan mengetahui campuran Ampas Tahu dengan menggunakan metode Marshall,untuk mengetahui kadar aspal optimum yang dihasilkan pada campuran aspal beton dengan filler Ampas Tahu, ditinjau dari stabilitas marshall, flow, VIM, VMA, VFB, dan MQ.Hal ini belum banyak dilakukan peneliti lain.Metode campuran aspal beton dalam penelitian ini menggunakan aspal minyak AC 60/70.Penelitian ini terdiri dari 5 sampel, masing-masing menggunakan kadar aspal yang berbeda yaitu: 5%, 5,5%, 6%, 6,5%, 7% (satu sampel = 3 varian).Tahapan penelitian meliputi agregat kasar batu koral tertahan saringan no. 8 (2,36mm), agregat halus dengan pasir sungai brantas lolos saringan no.8 (2,36mm), dan filler menggunakan ampas tahus dengan lolos saringan no. 200 (0,075mm).Hasil dari penelitian ini pada karakteristik Marshall didapat kadar Aspal Optimum 5% dan 6% dengan nilai rerata Stabilitas 712 dan 881, Flow 3,3 mmdan 2,4 mm, VIM 4,65% dan 4,24% VMA19,29%dan 17,87%, nilai VFB 75,41%dan 76,15%, dan MQ 271 kg/mm dan 433kg/mm.

Concrete is an important material in construction because it is necessary to improve the quality of concrete. One of the quality of concrete is influenced by the presence of air cavities in the concrete. The air cavity in concrete can be reduced by vibrating. The vibrating air cavity in the concrete will rise to the surface in the form of water. The purpose of this study was to determine the effect of the amount of water that rises to the surface as a result of vibrations on the concrete compressive strength of fc’21.7 MPa. The method used in this research is the experimental method and the study of previous research theories. Vibration uses an external vibration method with the acceleration of 180 m/s2, variation velocity 160 mm/s, and displacement of 1000 mm. The time variations used are 1 minute, 2 minutes, and 3 minutes. The specimen is cylindrical, with a diameter of 15 cm and a height of 30 cm. The results showed the highest amount of water that was on the surface contained in the vibration with a time of 3 minutes with a compressive strength of 23.35 MPa and water content 0.78 gr.