Civil Engineering Dimension (E-Journal)
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DEVELOPMENT OF NON-DESTRUCTIVE MONITORING SYSTEM FOR CHLORIDE PENETRATION INTO REINFORCED CONCRETE STRUCTURES
Get PDFReinforced concrete structures in marine environment are subjected to chloride penetration, which significantly degrades the structural performance due to the occurrence of corrosion in the steel reinforcement. The performance degradation of the structures would reduce the intended service life and caused higher maintenance and repair cost. Therefore, system to monitor chloride penetration into reinforced concrete before the starting corrosion of reinforcement is indispensable. An embedded probe system to detect chloride penetration into concrete was developed in Japan. This probe consists of a cementitious material body and some number of wires as sensors, which are set in the shallow ditches around the probe body. The system detect the chloride penetration by monitoring the initiation time of wire corrosion, it also has the advantages of continuous monitoring and early warning on the onset of corrosion in the reinforcement. However, the probe had not yet had high sensitivity for detecting critical chloride content in concrete. Therefore to increase its sensitivity, four types of improvements, namely partial coating of the wires, waterproofing on the probe body, filling the ditches with porous material and supplying small current on the wires were evaluated in this study. From the experimental result, it was observed that supplying small current and partial coating of the wires could improve the sensitivity of the probe significantly, while waterproofing treatment on the probe body and filling the ditches did not have significant contribution
DILATANCY BEHAVIOR IN CONSTANT STRAIN RATE CONSOLIDATION TEST
Get PDFSubjected to remolded young clay, this paper shows that a lot of time dependent behavior in the standard consolidation (SC) and constant strain rate consolidation (CSRC) tests is represented systematically by a simple assumption concerning the time dependency of dilatancy. In the SC test, at the first stage of each loading step little dilatancy takes place and dilatancy begins to occur several minutes after step loading. In CSRC test, some time period after the stress state has entered the normally consolidated region, dilatancy tends to occur rapidly with the increase in stress ratio. Since most of dilatancy has taken place at the earlier stage of consolidation, little dilatancy occurs at the latter stage of CSRC process. This tendency makes the specimen stiffer with the passage of time, and makes the vertical pressure and pore pressure increase substantially at the last stage of CSRC process. Consideration to such behavior may be effective to correctly interpret the result of CSRC test
THE SWELLING OF EXPANSIVE SUBGRADE AT WATES-PURWOREJO ROADWAY STA. 8 127
Get PDFDamage of structures and road beds due to expansive soil are common in Indonesia. One example is the deterioration of a road section at Sta. 8 + 127 of the Purworejo-Wates Highway. This Technical Note presents the investigation of the cause of the deterioration of the road bed. The author concludes that the sub grade is an expansive soil and the swelling pressure is able to lift the overlaying pavement and cause considerable cracking.
Abstract in Bahasa Indonesia :
Kerusakan struktur bangunan dan perkerasan jalan karena tanah ekspansif merupakan masalah yang banyak terjadi di Indonesia. Salah satu kerusakan perkerasan jalan yang terjadi karena tanah ekspansif adalah kerusakan perkerasan jalan di Sta. 8+127, Jalan Raya Purworejo-Wates. Technical Note ini menyajikan penyelidikan penyebab kerusakan perkerasan jalan tersebut. Penulis menyimpulkan bahwa tanah dasar di lokasi tersebut adalah tanah ekspansif dengan tekanan mengembang yang sanggup merusak struktur perkerasan jalan di atasnya
PENELITIAN PENDAHULUAN HUBUNGAN PENAMBAHAN SERAT POLYMERIC TERHADAP KARAKTERISTIK BETON NORMAL
Get PDFThe objective of this research is to explore the effect of adding polymeric fiber to the characteristics of normal concrete (fc’= 30 MPa). Two types of fiber, namely polypropylene and nylon, are considered. The research tested four types of concrete characteristics, namely compressive strength, flexural strength, modulus of elasticity, and cyclical loading. According to the analyses, linear regression with linearity in parameter can explain good relationship. All models developed can explain the variability of the data and are significant in the 0.05 level of significance, except for the relationhip between compressive strength and modulus of elasticity with percentage of nylon. Quadratic function was developed for the relationship between fiber content with the compressive strength, flexural strength, and modulus of elasticity. An efficient model was created by simultaneously modeling the relationship of compressive strength, fiber content, including the age of concrete. Model with logarithmic function was developed for the relation between number of cyclic loading and content of polypropylene, but not for nylon. Analysis showed that the model between cyclical loadings with polypropylene content was better compared with nylon content.
Abstract in Bahasa Indonesia :
Tujuan penelitian ini adalah mendapatkan hubungan penambahan serat polymeric terhadap karakteristik beton normal (fc’= 30 MPa). Penelitian dilakukan dengan menggunakan dua jenis serat polymeric, yaitu serat polypropylene dan nylon. Penelitian ini menguji empat jenis karakteristik beton, yaitu kuat tekan, kuat lentur, modulus elastisitas, dan pembebanan berulang. Analisis menunjukkan bahwa model regresi linier dengan kelinieran pada parameter dapat menjelaskan hubungan dengan baik. Seluruh model yang dibangun mampu menjelaskan variabilitas data dengan baik dan juga merupakan model yang signifikan pada tingkat keterandalan 0,05, kecuali model hubungan antara kuat tekan dan modulus elastisitas dengan kadar serat nylon. Model dengan fungsi kuadratis dibangun untuk hubungan kadar serat dengan kuat tekan, kuat lentur, dan modulus elastisitas. Suatu model yang efisien telah dibangun untuk menggambarkan hubungan simultan antara kuat tekan, kadar serat, dengan juga melibatkan variabel umur beton. Model dengan fungsi logaritma dibangun hanya untuk hubungan antara jumlah pembebanan berulang dengan penambahan serat polypropylene, namun tidak pada serat nylon. Analisis menunjukkan bahwa model hubungan pembebanan berulang dengan serat polypropylene lebih baik dibandingkan dengan model untuk serat nylon
PREDIKSI WAKTU LAYAN BANGUNAN BETON TERHADAP KERUSAKAN AKIBAT KOROSI BAJA TULANGAN
Get PDFConcrete is known as a porous building material, this can causes materials outside the concrete mass infiltrate into the concrete. Concrete structures constructed around the beach/seashore tend to have deterioration problems due to salt attack. This paper discusses models to predict the service life of concrete structure based on the deterioration problems. The service life of concrete structure is divided into three periods. Period I is time needed by Cl−ion to infiltrate into concrete up to the surface of the reinforcement, period II is time needed by corrosion products to fill the transition zone pores, and period III is deterioration time. The value of parameters used in the proposed equations is derived from the result of experiments. Finally, the proposed equations were evaluated by the relationship between variations of depth of concrete cover, water cement ratio (W/C) and distance of structure from shore line with service life. It could be concluded that the results of the prediction is satisfactory.
Abstract in Bahasa Indonesia :
Beton dikenal sebagai bahan bangunan yang berpori. Sifat ini menyebabkan senyawa dari luar dapat berinfiltrasi ke dalam beton. Bangunan beton yang dibangun di sekitar daerah pantai/laut cenderung mengalami kerusakan akibat serangan garam klorida. Makalah ini mendiskusikan model untuk memprediksi waktu layan bangunan beton terhadap kerusakan akibat korosi baja tulangan. Waktu layan bangunan beton dibagi menjadi tiga periode. Periode I adalah waktu yang dibutuhkan oleh ion Cl− untuk melakukan infiltrasi sampai ke permukaan baja tulangan, Periode II adalah waktu yang dibutuhkan oleh senyawa hasil korosi untuk mengisi pori-pori yang ada di transition zone, dan Periode III adalah waktu kerusakan pada bangunan beton. Parameter-parameter yang digunakan dalam persamaan yang diusulkan ditentukan dari hasil pengukuran di laboratorium. Persamaan tersebut dievaluasi dalam hal hubungan antara variasi tebal selimut beton, water-cement ratio (W/C ), dan jarak bangunan dari pantai dengan waktu layan. Hasil prediksi waktu layan bangunan beton terhadap kerusakan akibat korosi baja tulangan dapat disimpulkan cukup memuaskan
SYSTEMATIC FORMULATION OF HIGH PERFORMANCE CONCRETE PAVEMENT
Get PDFFollowing a 25-1 fractional factorial design concept, an experiment was planned ; sixteen experimental mixes were calculated from a basic mix (cement : sand : aggregates : fly ash = 1 : 1.3 : 2.6 : 0.8 and W/C ratio of 0.37) and determined changes (cement = 0.1 ; sand = 0.1 ; aggregates = 0.2 ; fly ash = 0.04 and changing W/C ratio by 0.01) using Taguchi’s orthogonal array. Samples were made from each data point. Compressive strength and water absorption were determined after each of two curing conditions (a) 28 days in the water, (b) 28 days in the water and 32 days in the air after that. Mix no 12 [Cement : Sand : Gravel : Fly Ash = 0.9 : 1.2 : 2.8 : 0.76] was found to have highest compressive strength and lowest water absorption
THE BUILDER?S LIABILITY BEYOND THE DEFECTS LIABILITY
Get PDFThis paper reviews the obligations of a builder after the expiration of the contracted defects liability period using relevant decided cases. The common areas identified as forming the bedrock of litigation pertain to structural and dimensional stability, freedom from damp, durability, adequate drainage, good waste disposal works, and effective service installations. Particular reference is made to walls, roofs, and services, which from the pilot study account for about 46%, 23%, and 17% respectively of the total defects attributable to the builder. It is concluded that the builder is responsible for defects arising from his product till the effluxion of reasonable time, except he establishes an element of contributory negligence
COMPRESSIVE STRENGTH OF SOLID ROUND STEEL MEMBERS REINFORCED WITH SPLIT PIPE(S)
Get PDFResults of experimental investigation on the compressive strength of twenty solid round steel leg member specimens of lattice communication towers reinforced with one or two split pipe(s) are presented in this paper. The reinforcement was connected to the leg members either by means of U-bolts only or by means of U-bolts and end welding. It was found that bolt torque has no significant effect in the increase on the strength. It was also concluded that using two split pipes without end welding is better than using one split pipe with end welding. Based on the test results, a simplified and conservative design procedure in accordance to the Canadian and American Standards is proposed to determine the compressive strength of solid round steel leg members reinforced with split pipe(s)
THE INFLUENCE OF MOLDING WATER CONTENT AND LIME CONTENT ON THE STRENGTH OF STABILIZED SOIL WITH LIME AND RICE HUSK ASH
Get PDFThe strength gain of stabilized soils is not only influenced by the type and proportion of the stabilizers and its curing time, but also by the water content needed to maintain the reaction. The reaction of lime – RHA with soil is pozzolanic. Hence, the process will be subjected greatly by the amount of water to react with admixtures and the proportion of the stabilizer. This paper presents the result of a laboratory study on the unconfined compressive strength (UCS) of soils stabilized with lime and RHA, compacted at the OMC, and at the dry and wet side of OMC. The amount of lime required for stabilization (LRS) is determined by Eades and Grim's Method. The results showed that the water content determines the UCS characteristics of unstabilized and stabilized soils. The UCS of stabilized soils decreased with increasing molding water content, but it is still higher than of the un-stabilized soils. In general, higher lime content results to a higher UCS. The maximum strength of the stabilized soil is attained at lime/RHA ratio of 1/2. The UCS of the stabilized soil increased significantly about 7 – 9 times to the un-stabilized UCS
ANALISA DAN EVALUASI SISA MATERIAL KONSTRUKSI SUMBER PENYEBAB KUANTITAS DAN BIAYA
Get PDFWaste material is a crucial problem in building construction. By minimizing waste materials, contractors can increase their profit and minimize the environmental impacts. This research is conducted to obtain the quantities of construction waste material, influencing factors, classify waste materials into direct waste and indirect waste, and propose a cost model of construction waste materials on shop-houses projects. Data are collected by questionnaire survey and construction site observation. The research findings indicate that quantities of bricks and sand waste are the biggest. Cost model findings indicate that minimum value of waste material (good waste management practice) are 3,33%, and maximum value (poor waste management practice) are 4,67% of construction budget for a shop-house building, so “potential waste saving cost” is equal to 1.34%.
Abstract in Bahasa Indonesia :
Sisa material merupakan salah satu masalah yang serius pada konstruksi bangunan. Usaha minimalisasi sisa material konstruksi akan membantu kontraktor untuk meningkatkan keuntungan dan mengurangi dampak lingkungan. Tujuan penelitian ini adalah untuk mengetahui kuantitas sisa material dan faktor-faktor penyebab, mengkategorikan sisa material berdasarkan direct waste dan indirect waste, dan mengusulkan suatu model biaya sisa material pada proyek ruko. Data penelitian diperoleh melalui survey penyebaran kuesioner pada para pelaku konstruksi, dan pengamatan di lapangan pada komplek proyek ruko di Surabaya. Hasil penelitian menunjukkan bahwa: (1) volume sisa material batu bata dan pasir adalah yang terbesar, (2) model biaya menunjukkan nilai minimum biaya sisa material (good waste management practice) sebesar 3,33%, dan nilai maksimum biaya sisa material (poor waste management practice) sebesar 4,67% dari total anggaran biaya satu ruko, sehingga Potential waste saving cost menjadi 1,34%