Praktikum Perkerasan Jalan Raya - Modul 12 Pemeriksaan Berat Jenis dan Penyerapan Agregat Halus

Summary

In this video, Vega explains the procedure for testing the specific gravity and absorption of fine aggregates in a practical lab session. The process involves several steps, such as soaking the aggregates, drying them, and determining their saturated surface dry (SSD) condition. Using tools like a digital balance, pycnometer, and oven, the video details the precise measurement and calculation techniques required for obtaining accurate results. The practical includes a four-day procedure, focusing on handling, measuring, and drying aggregates to assess their specific gravity and absorption capacity.

Takeaways

• 😀 The video explains a practical lab session on aggregate testing, specifically focusing on the determination of bulk density, water absorption, and other related tests on fine aggregates.
• 😀 The testing standards used are ASTM C-8574 and SNI 03 1970 1990, which outline the procedures for measuring the properties of fine aggregates.
• 😀 The goal of the practical session is to determine the bulk density, SSD (Saturated Surface Dry) state, and absorption percentage of fine aggregates.
• 😀 The necessary equipment includes a spatula, a heated pan, gloves, sieves, a 500ml pycnometer, digital scales, a conical funnel, and an oven.
• 😀 In the first part of the procedure, 750 grams of fine aggregates are sifted through a No. 4 sieve and soaked in water for 24 hours.
• 😀 After 24 hours, the excess water is drained, and the aggregates are dried in a preheated pan to a semi-dry state before being allowed to cool.
• 😀 A SSD test is conducted by placing the fine aggregates in a conical funnel, gradually adding and tamping the aggregates in thirds until a stable form is achieved.
• 😀 After confirming the SSD condition, the pycnometer is weighed, filled with water to 90% of its volume, and then the fine aggregates in SSD state are added.
• 😀 The pycnometer is then weighed again with the fine aggregates and water inside to ensure that all air is removed from the aggregate pores.
• 😀 On the final day, the aggregates are removed from the pycnometer, washed with water, and dried in an oven at 110°C for 24 hours before the final weight is measured.
• 😀 Once the aggregate is completely dried, its weight is recorded, and the data is used for further calculations and analysis of the fine aggregate's properties.

Q & A

What is the main objective of the practical experiment described in the video?

The main objective of the experiment is to determine the specific gravity, water absorption, and effective specific gravity of fine aggregates, as well as the SSD (Saturated Surface Dry) condition of the aggregates.

Which standards were followed during the experiment?

The experiment followed the ASTM 8574 and SNI 03 1970 1990 standards for testing the fine aggregates.

What equipment is required for this experiment?

The required equipment includes a spatula, a stove, a pan, gloves, sieves (No. 38, No. 4, and No. 200), a gas cylinder with regulator, a 500ml pycnometer, a digital scale, a container, a cone, glass plate, pestle, and an oven.

How is the fine aggregate prepared for the experiment?

The fine aggregate is first weighed and then soaked in water for 24 hours at room temperature. After soaking, the water is drained, and the aggregate is dried in a heated pan while being stirred.

What is the purpose of the SSD test in this experiment?

The SSD test is performed to check the state of the fine aggregate after it has been dried to a saturated surface dry condition. This helps in understanding the aggregate’s water absorption and its impact on its specific gravity.

How is the SSD condition of the aggregate tested?

The SSD condition is tested by placing the fine aggregate in a cone and compacting it in three stages, using a pestle to compact each section with 25 strokes. The condition is considered satisfied if the aggregate collapses but retains its shape.

What is the significance of using a pycnometer in this experiment?

The pycnometer is used to measure the volume of the fine aggregates accurately, allowing for the determination of their specific gravity by comparing the weight of the aggregate and the water it displaces.

How is the fine aggregate added to the pycnometer?

After the SSD condition is reached, the fine aggregate is carefully added into the pycnometer, filling it up to 90% of its volume with water, ensuring that no aggregates spill out during the process.

What happens to the fine aggregate after being placed in the pycnometer?

Once the fine aggregate is in the pycnometer, the mixture is allowed to sit for 24 hours. The pycnometer is then weighed, and after draining the water, the fine aggregate is dried in an oven at 110°C for 24 hours.

What steps are taken to finalize the experiment?

After drying the aggregate in the oven, the weight of the fine aggregate is measured, and calculations are performed to determine its specific gravity, water absorption, and effective specific gravity. The results are recorded, and the equipment is cleaned.