This study was aimed at determining the hardened and fresh properties as well as the high-temperature resistance of high-strength concrete (HSC) produced by incorporating diatomaceous earth, polypropylene, and glass fibers. CDE (calcined diatomaceous earth) was employed as a 10% cement replacement, while polypropylene and glass fibers were added separately to the mixtures at 0.2, 0.4, 0.6, 0.8, and 1.0% volumetric contents. Moreover, the mixtures without using CDE and fibers were used as references. The concrete mixtures were fabricated, followed by the determination of the fresh concrete flow, the absorption capacity, and the flexural, compressive, and splitting tensile strengths of hardened concrete. Furthermore, the specimens fabricated for the hardened concrete were exposed to temperatures of 400 °C, 500 °C, and 600 °C, and the remaining compressive strength was examined. The findings suggested that the incorporation of polypropylene and glass fibers in HSC with CDE enhanced the compressive, flexural, and splitting tensile strengths by 23.4 and 32.6%, 70.0 and 83.5%, and 18.9 and 17.9%, respectively. Moreover, the inclusion of polypropylene and glass fibers reduced the absorption of hardened concrete. Meanwhile, the inclusion of CDE lowered the strengths and increased the absorption. It was further identified that the incorporation of CDE enhanced the resistance of HSC to high temperatures, while polypropylene and glass fibers lowered the resistance. The incorporation of CDE, polypropylene, and glass fibers also lowered the flow of fresh concrete.

Original reactive powder concrete (RPC) consists of a large amount of cement, fine sand, crushed quartz, and silica fume, with a very dense matrix achieved by optimizing the granular packaging of the materials. This study, therefore, applied the modified Andreasen & Andersen particle-packing model using Aceh quartzite powder to design a densely compacted matrix and low cement content RPC mixtures. The research involved the preparation of two series of the mixture with different percentages of silica fume and Aceh quartzite powder and the 70.7 mm cube specimens were treated with combined steam curing and normal curing after which their compressive strength was tested at the age of 7 days and 28 days. The result showed the use of 61% local quartzite powder by weight of cement through an optimized mix design and cured treatment improves the RPC strength at any variation of silica fume.

Concrete is a building material that consists of a mixture of aggregate and paste. Normal concrete has a unit weight of 2200 kg/m3 to 2500 kg/m3. In addition to normal concrete, lightweight concrete is also known which has a unit weight of less than 1900 kg/m3. The research was conducted to produce lightweight concrete by using aggregate from polyethylene terephthalate (PET) plastic waste as a substitute for coarse aggregate. This study used 40 cylindrical samples of 150 mm x 300 mm with variations in the use of PET aggregates of 25%, 50%, and 100% of the volume of coarse aggregate. The results show that the use of PET aggregates produces concrete with a decrease in compressive strength of 26%–39% and a decrease in water absorption of 2%–32% from normal concrete. Ultrasonic Pulse Velocity (UPV) testing showed that the concrete with PET aggregates had a lower wave propagation velocity compared to normal concrete. Moreover, Schmidt hammer and splitting tensile test showed that concrete with PET aggregates had lower rebound number and split tensile strength compared to normal concrete. PET substitution percentages of 25% and 50% resulted in unit weights of 2218 kg/m3 and 2102 kg/m3, respectively, which rule out the use of lightweight concrete. However, 100% PET substitution has a unit weight of 1855 kg/m3 with a compressive strength of 14.16 MPa, which can be categorized as moderate structural lightweight aggregate concrete.

Every construction project faces constraints of cost, schedule, and quality that must be managed to achieve the desired objectives. This research aims to control the aspects of time and cost in construction projects by applying the Earned Value Concept and Crash Program methods. The subject of the study is the Preservation of Roads and Bridges project in Bireuen City - BTS, Lhokseumawe/Aceh Utara, Krueng Mane Buket Rata, SP. Krueng Geukeueh - PEL. Krueng Geukeueh (PEL. Lhokseumawe). The data analyzed includes the Budget Plan (RAB), project schedule, and reports on planned and actual work. This data is processed into three main indicators: BCWS, BCWP, and ACWP, which are then analyzed through Schedule Variance (SV), Cost Variance (CV), Schedule Performance Index (SPI), and Cost Performance Index (CPI). The analysis results show that during weeks 22 to 23, the project had a positive Schedule Variance (SV) (0), which then turned negative during weeks 24 to 28, with an average Schedule Performance Index (SPI) of 1.0096, indicating that project execution was ahead of schedule. Meanwhile, the Cost Variance (CV) was positive throughout the project, and the average Cost Performance Index (CPI) was 1.2118, indicating that actual costs did not exceed the budget. The application of the Crash Program method resulted in changes in heavy equipment rental costs and worker wages, from IDR 1,440,469,946.99 over 50 days to IDR 1,853,072,988.06 over 25 days, with a cost increase of IDR 412,603,041.07 and an acceleration ratio of 1.29. This research demonstrates that the Earned Value Concept and Crash Program methods are effective in controlling time and cost in construction projects, thereby helping to achieve better efficiency in project management.

Perancangan campuran beton (mix design) merupakan upaya untuk menentukan besarnya jumlah semen, agregat halus, agregat kasar, dan air yang akan digunakan dalam 1 m3 adukan guna memperoleh kuat tekan rencana dan kemudahan kerja yang ditetapkan. Aspek keuntungan ekonomis campuran beton sangat ditentukan dari jumlah kandungan semen. Campuran beton dengan packing density yang baik akan menghasilkan jumlah kandungan semen yang lebih sedikit. Penelitian ini bertujuan untuk mengoptimalkan komposisi campuran beton dengan menggunakan metode Andreasen-Andersen packing model berbantuan perangkat lunak EMMA. Hasil penelitian menunjukkan bahwa penggunaan metode Modified Andreasen Packing Model menghasilkan campuran beton berkandungan semen lebih rendah, dan kuat tekan beton pada umur 28 hari lebih tinggi dibandingkan dengan metode SNI 03-2834-2000. Pada mutu beton rencana 15 MPa – 25 MPa, penggunaan semen lebih rendah 6% - 9% dan kuat tekannya meningkat sebesar 6% - 7%. Selanjutnya pada mutu beton rencana 30 MPa – 40 MPa, penggunaan semen lebih rendah 14% - 27% dan kuat tekannya meningkat sebesar 5% - 13%.