A Study on the Flexural Behavior of Plain Cement Concrete with Self Compaction Concrete

To study the flexural behaviour of plain cement concrete with self-compaction concrete using three point loading. We are using two different types of concrete (Plain Cement Concrete and Self Compaction Concrete). For this we are using M20 grade concrete. We cast cubes and beams of sizes 150x150x150mm and 150x150x700mm respectively.Based on the test results it is concluded that the flexural strength of the self-compaction concrete beams is more than the plain cement concrete beams. And in the combination also the flexural strength is more when the plain cement concrete layer is at the bottom while the selfcompaction concrete layer is at top.

A Spiral Distributed Monitoring Method for Steel Rebar Corrosion

This paper proposes a novel spiral-wound, optic-fiber sensor to monitor the corrosion of steel bars. At the same time, the winding parameters, such as winding angle and pitch, were first theoretically deduced. Then, to decrease light loss, a practically distributed sensor wound onto the protective mortar layer was developed by increasing the winding curvature radius. The spiral distributed sensors were experimentally verified for their feasibility. Experimental results showed that the spiral fiber strain depended on the thickness of the protective mortar layer. Furthermore, the spiral distributed strain well reflected the cracking process of concrete. In addition, the concrete cracking time depended on the thickness of the protective concrete layer. Accordingly, this method is feasible for evaluating the initial and final cracking behaviors of concrete structures and provides a sight for steel bar corrosion.

Flexural Behaviors of Precast Reinforced Concrete -EPSfoam-Steel Deck Hybrid Panel

This paper presented the flexural behavior of the newly developed hybrid panel which included the comparison of the ultimate load, load-deflection behavior, and failure modes. The experimental study was carried out on precast reinforced concrete-EPSfoam-steel deck hybrid panels (CES)� consist of three layers of material : concrete� layer is on the top, the steel deck is located on the bottom layer, and the EPS foam layer as the core. The dimensions of CES are 300 mm x 1200 mm with thickness of concrete layer and EPS foam as variables. The concrete thick were 30 mm and 40mm. The density of EPS foam was 12 kg/m3, 20 kg/m3, and 30 kg/m3. The static flexural test of CES was conducted in accordance with the ASTM C 393-00 standard for determination of flexural strength on concrete, the load was applied at third-point loading. This test was carried out with monotonic static load, deflection control using a loading frame with capacity of 10 kN. The results show that increase the thickness of the concrete layer from 30mm to 40mm with� EPSfoam density of 12 kg /m3, 20 kg/m3, and 30 kg/m3 achieved a maximum load increase of 33.51%; 46,13%; and 37.35%, respectively.

Eksplorasi dan analisis kondisi perkerasan jalan pada jembatan rangka baja Soekarno-Hatta Malang pada bulan Maret 2015 menggunakan metode ground penetrating radar (GPR)

This research that purpose to explore and analyz the structure condition of pavement on the Soekarno-Hatta’s Malang truss bridge by using GPR method. GPR is used to knowing type of material objects based on dielectric constant of every materials, and to showing deformation, cracking, release structure, and water seepage. Data collected by observation techniques and retrieval of data sanples at 101 point of the track. Analysis starts from the stage of processing by using Ms.Excel, notepad, paint, software GeoScan32, and interpreted using software Surfer 9.0. The result is showing that the road pavement structure consists of a flexible pavement asphalt and rigid pavement concrete by identified the type of material is dry asphalt, wet asphalt, dry concrete, wet concrete, and air on surface. Deformation occurred in all of track pavement and there are a few sample points are experienced track surface defect such as cracks and release the structure. The most damage with average value 1.67and 1.69 that occur on the second and third of track, start from track 34-67 and 68-100. The postiton is located in point 33-66 m dan 67-99 m from Surabaya (north of bridge). Mapping result of cracking and release structure showing that 90 percent of pavement on Soekarno-Hatta’s bridge are damage. Water seepage that occur when the water breaking through the subsurface layers (asphalt) until concrete layer in base ground by content wet materal. Data distribution of pavement area that most occur water seepage on track 35-67 it’s on point 33-66 m. Penelitian ini bertujuan untuk mengeksplorasi dan menganalisis kondsi struktur lapisan perkerasan jalan pada jembatan rangka baja Soekarno-Hatta Malang dengan metode Ground Penetratig Radar (GPR). GPR digunakan untuk mengetahui jenis material objek berdasarkan konstanta dielektrik yang dimiliki setiap material, serta untuk melihat adanya defomasi, retak, pelepasan struktur, serta rembesan air. Pengumpulan data dilakukan dengan menggunakan teknik observasi lapangan dan pengambilan data sampel pada 101 titik lintasan di analisis dengan teknik deskriptif kuantitaif menggunakan Ms.Excel, notepad, paint, software GeoScan32, dan di interpretasikan dalam software Surfer 9.0. Hasil penelitian menunjukkan bahwa struktur perkerasan jalan terdiri dari perkerasan lentur aspal dan perkerasan kaku beton yang diketahui berupa lantai kendaraan dengan jenis material pada perkerasan yang dapat teridentifikasi adalah aspal kering, aspal basah, beton kering, beton basah,dan adanya udara dipemukaan. Deformasi terjadi pada semua lintasan dan di beberapa titik lintasan teridentifikasi mengalami retak dan pelepasan struktur. Kerusakan terbanyak dengan nilai rata-rata 1,67 dan 1,69 diketahui terjadi pada bagian yang kedua dan ketiga, yaitu dimulai pada lintasan ke 34-67 dan 68-100. Posisi terletak pada bentang ke 33-66 meter dan 67-99 meter dari arah Surabaya (utara jembatan). Hasil pemetaan retak dan pelepasan lapisan menunjukkan 90 persen dari perkerasan jalan pada Jembatan Soekaro-Hatta telah mengalami kerusakan. Rembesan terjadi ketika air menerobos lapisan permukaan (aspal) bagian bawah hingga menembus lapisan beton di dasar permukaan dengan indikator konten material basah. Data persebaran daerah perkerasan jalan yang banyak mengalami rembesan air terjadi pada lintasan 35-67 yaitu pada posisi bentang ke 33-66 meter.

PLANNING EVALUATION OF RIGID PAVEMENT’S THICKNESS ON INTERSECTION OF A ROAD SEGMENT OF SIKUI KM. 34 NATIONAL ROAD STA. 0+000 S/D 0+300 EAST BARITO DISTRICT

East Barito is one district that has a variety of natural resources such as agriculture and mining, Sikui KM of National Highway 34 is one of the roads that used to be accessed by one party mobilization of existing mines in Central Kalimantan. But on the other hand, the national road Sikui KM 34 is also used for connecting roads between provinces or cities. Based on the above actual national roads not intended for large-laden vehicles.Path planning is aimed to obtain a rigid pavement thickness based on the Pavement Design Manual Nomor 02/M/BM/2017 which controlled by “Pedoman Perencanaan Perkerasan Jalan Beton Semen Pd T-14-2003” and calculating the budget plan on the intersection of a road segment of Sikui KM 34 national road, East Barito disctrict.On the planning of rigid pavement’s thickness by using “Manual Desain Perkerasan Jalan Nomor 02/M/BM/2017” it is found that the concrete plate layer = 28,5 cm; LMC base layer = 10 cm; drainage layer = 15 cm and by using “Pedoman Perencanaan Perkerasan Jalan Beton Semen Pd T-14-2003” also found that the concrete plate layer = 21 cm; base layer = 15 cm. After that, on the existing condition obtained concrete plate layer = 30 cm; K-125 concrete layer = 10 cm. Then, it is found that the efficient pavement’s thickness which taken by using “Pedoman Perencanaan Perkerasan Jalan Beton Semen Pd T-14-2003” is more efficient rather than the existing condition. Moreover, this thesis also discusses the budget plan on the intersection of a road segment of Sikui Km. 34, East Barito district.

Thermal Resistance of Insulated Precast Concrete Sandwich Panels

Many nations are already working toward full implementation of energy efficiency in buildings known as Green Building. In line with this perspective, this paper aims to develop a thermally efficient precast concrete sandwich panels (PCSP) for structural applications. Therefore, an experimental investigation was carried out to determine the thermal resistance of the proposed PCSP using Hotbox method and the results were validated using finite element method (FEM) in COMSOL Multiphysics Software. The PCSP were designed with staggered shear connectors to avoid thermal bridges between the successive layers. The staggered connectors are spaced at 200 mm, 300 mm and 400 mm on each concrete layer, while the control panel is designed with 200 mm direct shear connection. In the experimental test, four (4) panels of 500 mm × 500 mm and 150 mm thick were subjected to Hotbox Test to determine the thermal resistance. The result shows that thermal resistance of the PCSP with staggered shear connection increases with increase in spacing. The PCSP with 400 mm staggered shear connectors indicates the best thermal efficiency with a thermal resistance (R value) of 2.48 m2K/W. The thermal performance was verified by FEA which shows less than 5% error coupled with a precise prediction of surface temperature gradient. This indicates that, with conventional materials, thermal path approach can be used to develop a precast concrete building with better thermal resistant properties. Hopefully, stakeholders in the green building industry would find this proposed PCSP as an alternative energy efficient load bearing panel towards sustainable and greener buildings.

Initial Parameters Affecting the Multilayer Doubly Curved Concrete Shell Roof

Doubly curved shell roof structures have been widely studied and applied in civil buildings, because of their compressive capacity. As a spatial structure, it should increase the space, reduce the thickness of the shell, and create the architecture for the building. In particular, reinforcement is needed to repair the shell surface, forming the multilayer curved shell roof structures. In this multilayer curved shell roof, it is necessary to investigate the influence of thickness of layers, the influence of the location of the steel fibres concrete layer, and the influence of steel fibres content contained in concrete on the state of stress and strain and build relationships, load-vertical displacement and stress in the x and y directions of the shell in the investigated cases. So, this paper presents an ANSYS numerical simulation study related to the state of stress and strain in double-layer doubly curved concrete shell roof with the initial parameters being changed such as the thickness of the layers, the location of the steel fibres concrete layer in the structure (the steel fibres concrete layer that is placed above and below the normal concrete layer), and the steel fibres content contained in concrete shell with the size of 3000 × 3000 mm, which is simulated by ANSYS after being experimentally conducted on this curved shell roof; the results of experimental and simulation study are verified by each other. Research results show that the thickness of the steel fibres concrete layer is placed below the normal concrete layer, the percentage of steel fibres contained in the concrete is 2%, and the bearing capacity of the curved shell is optimal.

Effect of the height of reinforced concrete layer on the mechanical properties of functionally graded concrete incorporating fly ash and polypropylene fiber

The present research aims to investigate the influence of the ratio of reinforced concrete layer height to total height (h/H) on the mechanical properties of functionally graded concrete (FGC) containing fly ash (Fa) and polypropylene (PP) fiber. All FGC samples were prepared with a constant water-to-cementitious materials ratio of 0.36 and ordinary Portland cement was replaced with Fa at 20% by mass. The reinforcement layer of FGC was enhanced with PP fiber inclusion (0.3% by volume of concrete). The effect of various h/H ratios of 0.25, 0.50, and 0.75 on the mechanical properties of the FGC samples was evaluated. The results show that flexural strength, flexural toughness, and compressive strength values of the FGC with PP fiber were higher than those of FGC without PP fiber at the age of 28 days regardless of Fa replacement. The experimental results also pointed out that the FGC samples prepared using an h/H ratio of 0.50 were beneficial in terms of mechanical properties.

Classification of Surface Pavement Cracks as Top-down, Bottom-up, and Cement-Treated Reflective Cracking Based on Deep Learning Methods

The treatment and repair strategies of reflective and fatigue cracking that initiate at the pavement surface (i.e. top-down cracking) and at the bottom of the asphalt concrete layer (i.e. bottom-up cracking) are noticeably different. However, pavement engineers are facing difficulties in identifying these cracks in the field as they usually appear in visually identical patterns. The objective of this study was to develop Artificial Neural Network (ANN) and Convolutional Neural Network (CNN) applications to differentiate and classify top-down, bottom-up, and cement-treated reflective cracking in in-service pavements using deep-learning models. The developed CNN model achieved an accuracy of 93.8% in the testing and 91% in the validation phases and the ANN model showed an overall accuracy of 92%. The ANN classification tool was developed based on variables related to pavement and crack characteristics including age, Average Daily Traffic , thickness of Asphalt Concrete layer, type of base, crack orientation and location.