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"The columns of a building must be stronger than the beams. The aim of this study is to obtain the cause of the long-term deformation difference by shrinkage between the beams and columns of high performance concrete with compressive strength of 60 MPa. This research was done experimentally in Indonesia during 410 days. Specimens measuring 150 mm × 150 mm × 600 mm were used, 3 pieces for the beams and 2 pieces for the columns. Deformation was obtained by using an embedded vibrating wire strain gauge for each specimen. The difference of long-term deformation in columns and beams is in their autogenous deformation behavior. This is because during the autogenous phase, swelling abnormally occurs in the column before shrinkage occurs. The abnormal swelling is caused by the press of its own weight. This phenomenon does not occur in beams. In the age range of 1 to 200 days, the behavior of the beam deformation has a similar pattern to the deformation behavior of the column with a high deformation rate. After that, at 200–410 days, column deformation changes to a very slow deformation rate. Long-term deformation in columns is lower (64%) than in the beams at 410 days age."

"Bekisting merupakan salah satu komponen dalam proyek yang memakan biaya cukup besar. Penggunaan bekisting berbahan woven polyethylene menjadi salah satu alternatif untuk menekan biaya bekisting. Penelitian ini berfokus pada wiremesh yang di gunakan sebagai penguat bekisting berbahan woven polyethylene, khususnya pada tie beam, di mana terdapat berbagai jenis jarak spasi wiremesh dan sudut putar pemasangan wiremesh hingga berbentuk intan. Identifikasi material yang di gunakan di lapangan, pembebanan akibat beton berdasarkan ACI 347-04 dan DIN 18218:2010, dan cara pemasangan wiremesh dan spreader cleats menjadi parameter yang perlu di dapatkan. Perhitungan deformasi akibat parameter tersebut di lakukan dengan bantuan aplikasi SAP2000 untuk memudahkan permodelan. Perbandingan nilai deformasi pada variasi permodelan jarak spasi wiremesh dan bentuk intan wiremesh perlu di bandingkan juga dengan data eksperimen yang telah di lakukan dalam penelitian sebelumnya oleh Novena pada tahun 2019 yaitu eksperimen Evaluasi Kinerja Bekisting Berbahan Dasar Woven Polyethylene pada Struktur Tie Beam dan Pile Cap. Selain itu, penggunaan aplikasi SAP 2000 juga berguna untuk mengetahui variabel yang di duga sensitif terhadap deformasi bekisting woven polyethylene. Variabel sensitif di tentukan dengan menggunakan sensitivity analysis terhadap variabel input pada aplikasi SAP2000, di mana metode yang di gunakan adalah koefisien korelasi Pearson dan analisa regresi.

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Formwork is one of components in the project that requires a large enough cost. The use of polyethylene woven formwork is an alternative to minimize the cost of formwork. This study discusses wiremesh which is used as a formwork reinforcement made from woven polyethylene, especially on tie beams, where there are various types of wiremesh spacing and rotational angles of wiremesh mounting to form diamond shape wiremesh. Identification of materials used in the field, loading using concrete based on ACI 347-04 and DIN 18218: 2010, and how to install wiremesh and spreader cleats are parameters that need to be obtained. Assessment of the required parameters above with the help of the SAP2000 application to facilitate modeling. Comparison of reform values ​​in the variation of distance modeling of wiremesh spacing and diamond shape wiremesh needs to be compared also with experimental data that have been carried out in research previously conducted by Novena in 2019, namely the experiment The Performance Evaluation of Woven Polyethylene on Tie Beam and Pile Cap Structure. In addition, the use of SAP2000 application is also useful for studying variables that are assumed to be sensitive to woven polyethylene formwork deformation. Sensitive variables are determined by using sensitivity analysis of input variables in SAP2000 applications, where it uses Pearson correlation coefficient method and regression analysis."

"Self-Consolidating Concrete (SCC) mixtures for use in Prestressed Concrete applications are evaluated in this paper . Twenty one SCC mixtures were made under laboratory conditions with varying water to cementitious materials ratios, sand to total aggregate rations, and cementitious materials combinations (type III cement , class C fly ash, ground-granular blast-furnance slag, and silica fume). The SCC mixtures archived prestress transfer compressive strengths between 5470 and 9530 psi (38 and 66 MPa). The moduli of elasticity of the SCC Mixtures were in reasonable agreement with the elastic stiffness assumed during the design of conventional slump concrete structures. The long term drying shrinkage strain for all the SCC mixtures were approximately the same or less than those measured for the control mixtures. A change in sand to total aggregate ratio had no significant effect on the long term drying shrinkage. At later ages of 56 and 112 days, the measured drying shrinkage corresponded reasonable well to those predicated by the ACI 209 procedure."

"internal curing is promoted as a way tpo mitigate autogenous shrinkage in high-performance concrete having a low water binder ratio (w/b). Different methods of internal curing have been proposed. In this study, the effect of substituting 20% of normalweight sand by an equal mass of lightweight sand on the development of shrinkage was investigated on a 0.35 w/b high performance concrete . Shrinkage was monitored using vibrating wire gauges cast at the center of 100x100x400 mm (4x4x16 in.) concrete samples. Two samples were sealed with self-adhesive aluminum foil to present a closed curing system without any exchanged of humidity between the concrete and its environment, After demolding at the age if 23 to 25 hours. two other samples were cured under water for 6 days . Thereafter these two samples were removed from water and maintained at 23 C (73 F ) and a 50% relative humidity (RH) Environment . Experimental results clearly demonstrate the effeciency of a 20% substitution of normalweight by a lightweight sand to reduce autogenous and drying shrinkage . The Incorporation of 20% lightweight sand did not significantly affect the 28-day compressive strength. The cementitious matrix presented low chloride ion permeability. Internal curing through the use of partial replacement of normalweight sang by lightweight sand definitely represent and efficient method to diminish autogenous and drying shrinkage in low w/b concretes where external water curing does not allow in-depth curing of concrete"

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ABSTRACTThe aim of this research is to reproduce the experimental result using finite element approach with damage model coupled to creep. The calibration of coupling between creep and local damage model associated with size effect law proposed by Bazant are presented in this thesis. Its behavior was investigated through two kinds of studies, the loading rate effect and residual capacity test. Three different sizes of beam, which are geometrically similar specimens, were simulated in three point bending test and creep test divided into load level test and residual capacity test. Numerical simulation was doneusing existing finite element code Aster_ Code developed by EDF (Eiectricite de France) for coupling between local damage based on bi-linear elasto-damage model and creep based on Benboudjema theory. Result show that the finite element code is capable to reproduce the experimental result qualitatively. The interaction between creep and local damage is shown through size effect plot by giving the behavior shift to the right, which means that the materials become more brittle when creep appears.
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