WorksheetsSoal UAS BIT PTB B Tahun 2025
Total questions: 40
Worksheet time: 20mins
The primary purpose of the Flow Table Test for cement mortar is to evaluate its...
Compressive Strength
Time of Setting
Consistency
Unit Weight
In the Flow Table Test procedure, what action must be performed immediately after the mold is filled and excess material is struck off?
Apply a final compaction load.
Measure the initial diameter of the specimen.
Lift the conical mold vertically and slowly.
Add a small amount of water to the table surface.
A high flow percentage result in the Flow Table Test indicates which of the following characteristics for the cement mortar?
Low cohesiveness and stiffness.
Good particle interlocking.
High workability and fluidity.
Excessive early strength gain.
Why is the spread diameter measured in several different directions after the drops are completed? (on Flow Table Test)
To determine the volume of the specimen.
To calculate the density of the cement.
To account for any non-uniformity in the specimen spread.
To verify the number of drops applied.
If a mortar mix consistently yields a Flow result far below the specified minimum, which component is most likely insufficient during sample preparation, affecting workability? (on Flow Table Test)
Cement content.
Fine aggregate amount.
Air entrainment.
Mixing water proportion.
The Rebound Hammer Test (Schmidt Hammer) is primarily used to estimate which property of concrete?
Modulus of Elasticity
In-situ Compressive Strength
Tensile Strength
Water Absorption
The Rebound Hammer Test
Destructive Test (DT)
Semi-Destructive Test (SDT)
Non-Destructive Test (NDT)
Abrasive Test
What is the essential purpose of using a calibration anvil before carrying out the Rebound Hammer Test on a concrete structure?
To polish the surface of the concrete test area.
To determine the exact test point locations.
To ensure the hammer's mechanics provide accurate.
To measure the moisture content of the concrete.
A higher rebound number obtained from the Schmidt Hammer test generally implies which characteristic of the concrete under the surface?
Lower density and higher porosity.
Greater surface flexibility.
Higher surface hardness and estimated strength.
A larger proportion of coarse aggregate.
Why must the rebound numbers be correlated with laboratory-determined strength curves instead of being directly used as the definitive compressive strength? (on Rebound Hammer Test)
Because the test requires excessively long reading times.
Because the result is only affected by the coarse aggregate size.
Because surface conditions affect the reading.
Because it can only be used on very young concrete.
The Aggregate Crushing Value (ACV) Test is designed to evaluate which fundamental characteristic of aggregates?
Resistance to abrasion.
Water absorption capacity.
Resistance to gradually applied compressive load.
Specific gravity.
In the Aggregate Crushing Value (ACV) test, how are the 'fines' produced by crushing separated and quantified?
By measuring the volume of water displaced by the sample.
By observing the number of cracks in the aggregate after loading.
By weighing the aggregate material that passes through a specific sieve.
By measuring the diameter of the largest remaining particle.
What does a high Aggregate Crushing Value (ACV) indicate about the quality of the aggregate material?
The aggregate is very durable and wear-resistant.
The aggregate is relatively weak and susceptible to crushing.
The aggregate has low water absorption.
The aggregate is suitable for all types of construction layers.
For the Aggregate Crushing Value (ACV) Test, the load must be applied at a uniform rate. What is the fundamental reason for this controlled loading rate?
To ensure the aggregate particles heat up evenly.
To prevent the testing machine from overheating.
To standardize the rate of stress accumulation.
To measure the elasticity of the material.
Aggregates with a high Aggregate Crushing Value (ACV) are generally restricted from use in which critical component of road pavement?
Filter layers in the drainage system.
The wearing course (surface layer).
Earthworks and embankments.
Lightweight concrete elements.
The Aggregate Soundness Test apparatus is primarily used to assess:
High-speed abrasion.
Hydraulic pressure.
Weathering, such as freeze-thaw cycles.
Chemical leaching of the material.
Which chemical solution is commonly used in the Aggregate Soundness Test to induce expansive pressure within the aggregate pores during the drying cycle?
Hydrochloric Acid (HCl)
Potassium Chloride (KCl)
Magnesium or Sodium Sulfate
Calcium Hydroxide (Lime)
What is the primary physical mechanism that causes the disintegration of susceptible aggregate particles during the drying phase of the Soundness Test?
Rapid cooling and thermal shock.
Hydration of the aggregate minerals.
Expansion pressure from salt crystallization.
Chemical dissolution of the aggregate matrix.
How is the final result of the Aggregate Soundness Test typically reported?
As the total volume change of the aggregate sample.
As the number of cycles required to cause total failure.
As the percentage of mass loss of the sample.
As the change in the specific gravity of the material.
Why is the Aggregate Soundness Test result considered critical for aggregates used in coastal protection structures or bridge decks in cold climates?
Because these environments require aggregates with extremely low density.
Because these structures are constantly exposed to repeated cycles.
Because the aggregates must have a very high crushing value.
Because the test results help determine the bitumen content.
The Permeability Test (Falling Head / Constant Head) is used to measure which?
Undrained Shear Strength.
Specific Gravity.
Coefficient of Permeability (k).
Consolidation settlement.
Which of the two main permeability test methods is typically preferred for coarse-grained soils like sand and gravel?
Falling Head Test.
Constant Head Test.
Vane Shear Test.
Standard Penetration Test (SPT).
What is the most critical condition that must be established for the soil specimen before any permeability test can commence?
The sample must be dried completely in an oven.
The soil sample must be fully saturated with water.
The sample must be mixed with cement or lime.
The sample must be compacted to its maximum dry density.
The fundamental governing principle for water flow in the Permeability Test is described by which law?
Hooke's Law.
Newton's Law of Viscosity.
Bernoulli's Principle.
Darcy's Law.
The Falling Head Permeability Test is considered more suitable for fine-grained soils (like clay) primarily because the test requires measuring:
The total volume of the soil specimen.
The high flow rate under maximum pressure.
The time it takes for a very small change.
The constant discharge under a steady head.
The Unconfined Compression Test (UCT) apparatus is best suited for determining the strength of which type of soil?
Dry, coarse sand.
Gravel and cobbles.
Cohesive soils (clays and silts).
Organic peat.
What is the specific strength parameter that the Unconfined Compression Test is used to determine?
The angle of internal friction ( ϕ ).
The ultimate bearing capacity.
The undrained shear strength ( cu ).
The coefficient of compressibility ( av ).
What is the critical defining condition of the Unconfined Compression Test that differentiates it from a typical Triaxial Compression Test?
It applies load rapidly, rather than slowly.
It requires the specimen to be fully drained.
The lateral confining pressure is equal to zero.
It uses a square specimen instead of a cylindrical one.
What type of physical failure mechanism is typically observed in a cylindrical cohesive soil specimen during the Unconfined Compression Test?
A. A general collapse or barreling without a defined plane.
B. Tension cracks forming at the specimen ends.
C. Shear failure along a distinct diagonal plane.
D. Complete pulverization into powder.
Why is the Unconfined Compression Test considered unsuitable for determining the strength of completely non-cohesive soils like dry sand?
Because sand is too stiff to be compressed.
Because sand's strength is purely frictional.
Because sand has a very high water content.
Because it only applies to disturbed soil samples.
The Marshall Stability and Flow Test is the standard method used to evaluate the design characteristics of which construction material?
Portland Cement Concrete.
Soil-cement mixtures.
Hot Mix Asphalt Mixtures.
Fine aggregate sand.
What are the two primary parameters measured by the Marshall Test apparatus?
Density and Voids in Mineral Aggregate (VMA).
Penetration and Viscosity.
Stability and Flow.
Resilience and Durability.
Why is the asphalt specimen heated to a standardized temperature (typically 60°C or 140°C) just before loading in the Marshall Test?
To increase the hardness of the bitumen binder.
To simulate the highest expected working temperature.
To ensure the specimen is completely dry.
To remove the effects of air voids in the mixture.
A high Marshall Stability value for an asphalt mixture indicates which desirable pavement characteristic?
High flexibility and low stiffness.
Good resistance to permanent deformation under heavy traffic.
Excessive amount of bitumen binder.
High sensitivity to temperature fluctuations.
In the Marshall mix design, why is it necessary to ensure that the Flow value is within an acceptable range, even if the Stability value is very high?
Because high flow is always desirable for all pavements.
To prevent the mixture from becoming too stiff.
To maximize the air voids in the mixture.
To increase the bitumen-aggregate adhesion.
The Softening Point Test (Ring and Ball Method) is performed to find a specific temperature characteristic of which material?
Mineral Aggregate.
Portland Cement.
Bitumen or Asphalt Binder.
Concrete Curing Water.
What object is placed on top of the bitumen sample in the brass ring to apply a constant load as the temperature increases? (on Softening Point Test)
A standard glass rod.
A steel ball.
A small brass plunger.
A thermometer bulb.
The softening point temperature is officially recorded when which specific physical event occurs?
The bitumen in the ring begins to melt and bubble.
The steel ball touches the bottom plate.
The bitumen changes color from black to brown.
The volume of the bitumen specimen doubles.
Why must the heating rate of the water (or glycerin) bath be controlled and uniform throughout the Softening Point Test?
To ensure the steel ball does not rust or corrode.
To prevent the bitumen from expanding excessively in volume.
To ensure the test results are consistent and independent of the test duration.
To maximize the adhesion between the bitumen and the brass ring.
If a bitumen binder exhibits a relatively high softening point, what is the beneficial implication for the performance of the asphalt pavement in hot climates?
The pavement will have greater resistance to low-temperature thermal cracking.
The bitumen will be easier to mix and compact.
The pavement will have improved resistance to rutting and permanent deformation.
The binder will have a higher penetration value.
