Bonding Capacity of Deform Bar in Sea Water Concrete

The seawater contains about 35,000 ppm is dissolved salt which can increase the risk of corrosion in steel reinforcement embedded in concrete.  This study aims to determine the value of bond strength of seawater concrete with steel reinforcement. This research uses experimental test method in laboratory which includes compressive strength test, concrete split tensile strength test, tensile strength of deform bar, pull out test and visual observation of carbonation test.  The specimens in this study was made in 3 different types of curing, i.e. wet curing, dry curing and wet-dry curing. The result of the research obtain the compressive strength for 28 days for dry curing is 17.15 MPa,  while for wet curing and dry-wet curing about 16.895 MPa and 19.367 MPa, respectively. The split tensile strength of concrete after 28 days for dry curing, wet curing, and dry-wet curing are 7.55 MPa, 8.85 MPa and 7.55 MP, respectively.  The bond strength specimen for 28 days in dry curing was 5.46 MPa, whereas specimen in the wet curing and dry wet curing showed bond strength about 5.94 MPa and 4.90 MPa, respectively. Based on the result, compressive strength in wet-dry curing showed higher value than others curing types, while specimen in wet curing presented the value of split tensile strength and bond strength higher than dry curing and wet-dry curing

Bond between Steel Reinforcement Bars and Seawater Concrete

In order to promote sustainable development in the remote islands this present research attempted to study the suitability of seawater, that available abundantly surrounding the remote islands with Portland composite cement (PCC) and crushed river stones to produce concrete. This research aims to utilize seawater, and Portland composite cement (PCC) to produce high-performance concrete in order to eliminate the main problems of clean water shortage in the low land areas and the remote islands. Infrastructure development can be sustained through the effective use of natural available local materials on the remote islands. The method used in this research is an experimental method in the laboratory. Two variations of concrete were made using freshwater and seawater, respectively as a mixing material with a water to cement ratio (w/c) of 0.55. The evaluation result on concrete compressive strength and bond strength of seawater concrete were discussed. Experimental results showed the compressive strength of the seawater concrete is lower by 6.26% as compared to the normal concrete at water-cement ratio (w/c) of 0.55. In addition, the bonding strength of steel bar embedded in seawater concrete is lower by 4.34% as compared to the bonding strength of steel bar embedded in normal concrete at water-cement ratio (w/c) of 0.55. Doi: 10.28991/cej-2020-SP(EMCE)-06 Full Text: PD

Palm fibers influence the compressive strength and CBR on soil cement

Soil cement is a mixture of soil with cement. The usefulness of this mixture is very meaningful to increase\ud the carrying capacity of the land. Weakness that accurs from this mix is the process by cement shrinkage and hydration.\ud This process can lead to cracks and effect the compressive strength and carrying capacity of the soil cement. With the\ud addition of fiber in this mix can reduce or even eliminate the process of shrinkage and hydration. Natural fibers as a\ud mixture of palm fibers, which can be obtained easily in the market and a lot cheaper. Tests carried out at the Laboratory\ud of Soil Mechanics, Department of Civil Engineering, Polytechnic of Samarinda, East Kalimantan. Testing the physical\ud properties and modified compaction test as a first step. The next stage is done in 3 stages: first the addition of cement\ud 10%, then the second stage of the addition of palm fibers (2,5%;5%;7,5%) and third stages 1% reduction in the amount\ud of cement in the soil-cement mixture with 5% palm fibers. Palm fibers can increase the compressive strength of soilcement\ud between 54,71%-68,38% and CBR between 1,91%-43,39%. Palm fibers 5% by weight of cement is an ideal\ud amount of soil-cement mixture

Experimental Model of Suction Head on Expansive Soil Subgrade with Concrete Wall Moisture Barrier

Soil expansivity generally occured caused by the presence of a clay mineral of smectite group, such as montmorillonite, illite, bentonite, etc, which could absorb so much water. The impact of losses incurred by soils ekspansivity on buildings and infrastructure primarily on lightweight structures are staggering. Technology is often applied as a solution to problems such as improvement of material characteristics, providing early treatment of constructive and structural engineering support to overcome the adverse effects of expansive soil. Erecting concrete moisture barrier on the side of the road is a combination of the provision of early treatment and support in structural engineering change control water content in the soil layer of expansive.This study aims to determine the behavior of suction, moisture barrier effects on suction head reduction, and the experimental model of suction head profile with the erecting and testing of the models tested in the laboratory.The test model was made to resemble half of the road width with a load of 30 kPa on it. On the side of the road mounted concrete wall moisture barrier with a variation of the depth of 20 cm, 35 cm and 50 cm. Observation of time and water absorption carried out on 8 observatories, also the amount of swelling through a dial that is placed above the concrete slab load. The results showed an increase in capillary water in front bulkhead for all variations of depth moisture barrier and water absorption height reduction occurred in the rear bulkhead respectively 3.25%, 21.25% and 45% for the ratio of height bulkhead and expansive soil thickness h/H = 0.44, h/H = 0.78 and h/H = 1.11. Also the reduction of swelling respectively by 4.46%, 52.69% and 82.53% for each ratio h/H above

An Eksperimental Permeable Asphalt Pavement Using Local Material Domato Stone on Quality of Porous Asphalt

The lot deposit of Domato Stone as local material from sea location in Banggai island in half Sulawesi of Indonesia. Was still not be exploited better. Some reseaarch in the field of road construction showed that Domato Stone was powefull enough when mixtured asphalt structure. Permeable asphalt pavement or porous friction course is commonly knows as porous asphalt. The porous pavement used in Japanes and europe. The pavement consists in a porous overlay allowing rainwater to flow down to the botton the overlay and then to drain on the edges of the pavement. Quality of porous asphalt was developed to drain pavement surface flow through itâs pores, because of is specific propertis to mesure itâs ability to drain the water ( Permeability ), a special measuring device is required. This study is aimed to measure the coefficient of permebility using the constanthead permeability test at transportation laboratory Hasanuddin University. The result were compared with the previous study. The test included horizontal and vertical permeability. There types of gradation were in comporated to : British Graduation, Binamarga Gradation, and Australian Gradation. The tests were carried out at optimum bitumen content, the result shows that the vertical permeability of porous asphalt usig British Gradation were : 0,0914, 0,2841 and 0,2912 Cm/sec. Respectively meanwhile for horizontal permeability were 0,1168, 03212, 0,2897 Cm/Sec. The Marshall stabilities were at in countary to the permeabilities, the porousity were comparable to the permeabilities. The results of research indicates that porous asphalt mixture showed an influence on the value of the characteristics of porous asphalt particularly at concrete waste fraction grading 50% retained 1/2 " and 50% natural crushed stone retained 3/8" where the values obtained from the analysis of optimum binder content is 9.5%. Based on the Scanning Electron Microscope (SEM) can be seen the microstructure and content of chemical elements present in the porous asphalt which prove that all elements of the liquid asbuton and concrete waste can blend and bind well