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Concrete is one of the construction materials has various advantages, namely the cost of work is cheaper than steel, another advantage is that it is easily formed as desired depending on the shape and strength of the formwork. At the stage of construction implementation in the field, there are often irregularities or errors that cause concrete damage. One of the damages in the field is that concrete that undergoes changes / developments not in accordance with the formwork made, this failure is often referred to as expanding concrete. The purpose of this study was to find out how the common causes of concrete damage, especially bunting concrete in the construction project of Hotel Rez Semarang. The data collection methods used in this study were literature studies, and observations in the field. The results of the analysis discuss the causes of concrete bunting are imperfect compaction, not strong formwork, non-slippery formwork, poor implementation in installing formwork and no reinforcement when installing formwork, so that the formwork is unable to withstand the weight of wet concrete during casting. One way is to implement a strict management system and regulations in the project, if all workers can be disciplined and comply with existing Standard Operating Procedures (SOPs), it can be ascertained that there will be a reduced error rate in the project. For this reason, the method of handling concrete bunting is by means of trimming and paching or grouting methods at damaged locations. [ABSTRACT FROM AUTHOR]

Columns are compression structural elements that play an important role in buildings. Collapse of columns can lead to complete collapse of the entire structure. Because the column functions as a vertical load support and is an important element in a building, damage to the column cannot be ignored. One of the damages that can occur in the column is porous. If porous occurs in the column concrete, it must be addressed immediately. Factors that can cause porous concrete are imperfect casting processes, dirty formwork, incorrect installation of reinforcing steel, inappropriate material ratios, and too fast dismantling of formwork. How to overcome porous concrete columns with the grouting method. Research related to the causes of porousness in columnar concrete uses descriptive research methods. Aims to describe what has happened during the research process. So that in this study resulted in the stages of the factors causing porousness in the column concrete of a building project. [ABSTRACT FROM AUTHOR]

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Cold form steel is one type of material that is currently experiencing very rapid development. The advantages of the using cold form steel are so many, one of which is the light weight and high quality steel. This is an added value for cold form steel. But one of the weakness in cold form steel profile is the buckling effect. So that additional fillers are needed so that cold form steel has resistance with buckling effect. Mortar is a filler that is often used in construction. Therefore this research will be discuss the analysis of grouting mortar to prevent buckling effect in the cold form steel profile. And then the grouting mortar that will be used uses a variation of cement to sand as big as 1:1, 1:2, 1:3 and 1:4. From the results of the compressive strength of the mortar obtained compressive strength of 1: 1 has the greatest compressive strength of 30 Mpa. And then for the flexural test, the steel beam with mortar variation 1: 1 has the greatest resistance of 9558 Newton, with the smallest deflection value of 8 mm and the greatest stress of 19.47 Mpa, when compared to steel beams with variations of 1: 2, 1: 3, 1: 4 and steel beams without fillers.

The applicability of bio-chemical grouting as the environmentally friendly and economically method for liquefaction remediation was evaluated. Several combinations of organic and in-organic precipitations methods were conducted to obtain the optimum grouting solution. Organic precipitation method employs a bio-agent of urease enzyme to dissociate urea into ammonium and carbonate ions. The produced carbonate ions are precipitated as calcite crystals in the presence of calcium ions. Meanwhile, the in-organic methods were performed using chemical compounds only, without the bio-agent. Unconfined compressive strength (UCS) tests were performed to evaluate the applicability of the grouting solutions for improving the soil strength. Grouting solution is injected into the prepared sand samples. The sand samples with a relative density of 50% were treated with one and two PV for 3-day curing times. The experimental results showed that the organic precipitation method produced the high precipitated amount and resulted in the significant improvement in the strength of the treated sand. The presence of the precipitated materials within the grains of soil generated the strength of 272 kPa. The results of this study have elucidated that the organic precipitation method composed of calcium chloride, magnesium sulfate, urea and enzyme of urease may be an alternative soil-improvement technique to prevent the liquefaction susceptibility.

Jembatan Suramadu yang akan menghubungkan kota Surabaya dengan Madura memiliki bentang total sepanjang 5.438 m. Mengingat lokasi pembangunan yang berada di laut dan beban rencana yang besar pada tiang pondasi, maka uji pembebanan statik konvensional tidak mungkin untuk dilakukan di jembatan utama. Alternatif tes pembebanan tiang yang dapat dilakukan adalah Tes OC yang mengikuti prosedur Osterberg Cell Test. Tes ini dilengkapi dengan load cell, telltale, dan strain gauge sehingga dapat diperoleh kurva load-displacement untuk tahanan ujung dan tahanan selimut pada berbagai kedalaman. Hasil penyelidikan tanah menunjukkan keberadaan lapisan tanah clay-shale yang mengandung montmorillonite pada lokasi tiang bor. Jenis tanah ini sensitif terhadap berkurangnya tegangan lateral akibat pemboran dan terhadap weathering process sehingga dapat terjadi strength reduction. Strength reduction tanah menyulitkan predikasi tahanan ujung dan tahanan selimut pondasi tiang bor. Hasil Tes OC digunakan sebagai acuan dalam menentukan pengaruh strength reduction terhadap tahanan ujung dan tahanan selimut dengan cara membandingkan hasil pengukuran dengan hasil prediksi berdasarkan korelasi empiris yang umum dipakai. Untuk tahanan ujung, hasil Tes OC menunjukkan harga yang relatif dekat dengan hasil prediksi sehingga strength reduction untuk tahanan ujung akibat pemboran relatif kecil selama kondisi dasar pondasi bersih. Sedangkan untuk tahanan selimut, hasil pengukuran nilainya jauh lebih kecil dibanding hasil prediksi. Untuk meningkatkan daya dukung, maka dilakukan grouting melalui ujung tiang. Hasil pengujian menunjukkan bahwa setelah dilakukan grouting pada pondasi terjadi kenaikan nilai tahanan ujung dan tahanan selimut. Dibandingkan dengan tahanan ujung, tahanan selimut memiliki peningkatan kekuatan yang lebih besar dan setelah dilakukan grouting nilainya mendekati nilai prediksi.

Abstract: The Impact of Sika Grout Addition on Grouting Mortar Toward Concrete Reinforcement Stickness with Copper Slag as Cementitious. The aim of this research is to identify the impact of Sika Grout addition on grouting mortar toward concrete reinforcement stickness with copper slag as cementitious. The experiment result of this research shows that (1) the addition of Sika Grout 215 in grouting mortar can improve the reinforcement stickness; (2) the use of 100% Sika Grout 215 in grouting mortar produces maximum stickness; (3) the stickness of 100% Sika Grout 215 has 12.800 kg stronger (2,8% of improvement) than those of using copper slag reinforcement (without grouting) as 12.450 kg; (4) the use of less than 100% Sika Grout produces less stickness of no-grouting reinforcement; and (5) there is similar slip characteristic between concrete reinforcement added with grouting and without grouting as 2,5 mm on outer part of the mortar.