slump test apparatus

Types of Slump Test Apparatus

Concrete pumpability is measured using a type of apparatus called the slump test. Concrete has a high consistency and is usually plastic. The slump test apparatus includes components of different kinds.

They include:

• Slump cone

  It is an abbreviated inverted cone that is open at both ends. The cone has a base whose diameter measures 20 centimeters and a top whose diameter measures 10 centimeters. Its height is around 30 centimeters. The cone also has a rim that is thin and a concrete cylinder shaped like a cone where concrete is placed during the test.

• Slump base plate

  This is a measuring board that has a flat surface placed underneath the cone to collect the concrete mixture. Usually made of steel or wood, it provides a stable base for the cone so that the concrete does not spread too much when placed.

• Slump cone lifting device

  It is optional and provides a cone that is lifted away from the mixture at a safe and steady manner. Many people use it to avoid jarring the cone since this may lead to bad concrete results.

• Ruler or measuring stick

  It is a slide gauge that is set beside the cone after it is removed from the mixture to measure the amount of slump that is there. The slump is defined as the distance between the top of the cone and the highest point of the slumped mixture.

Industrial Applications of Slump Test Apparatus

The apparatus for the slump test is mainly used in construction and civil engineering. It is used to check the workability of the concrete mix before pouring.

• Quality control in ready-mixed concrete plants

  Ensuring the mixture's consistency helps prevent variations that might affect structural integrity. Regular slump tests on available concrete ensure they meet required standards before delivery to construction places.

• Field testing at construction sites

  It helps determine whether a given mixture has the right level of workability needed for a specific job. Slump test apparatus measures pourability and adjusts the mixtures by adding water or plasticizers.

• Compliance with industry standards

  Slump is used as a basic measure of concrete workability by most of the body regulations in the construction industry. It makes sure that concrete mixtures meet safety and performance standards.

• Assessing impact of admixtures

  The slump test measures the effect of different admixtures on workability, which is important for projects with special needs. It is considered when chemical agents like superplasticizers are added to the mixture to evaluate their effect in increasing level of fluidity.

• Monitoring concrete during extreme weather conditions

  In places where temperatures are very high or low, slump test apparatus is used to adjust mixtures to increase resistance, like adding air-entraining agents during extremely low temperatures.

• Assessing Concrete Pumpability

  Slump test apparatus is important for testing concrete pumpability, especially in high-rise buildings or complicated structures. It better shows the capacity of concrete to flow through the pump, which affects the level of cost and time. Poorly mixed concrete causes blockages and requires extra time to clear or redo an entire section.

Product Specifications and Features of Slump Test Apparatus

Key Features

• Slump cone design

  The cone has a bottom diameter of around 20 centimeters, a top diameter of 10 centimeters, and a height of 30 centimeters. This variation in diameter gives the cone an inverted shape tapering from the larger base to the smaller top. This facilitates the concrete flow and shaping during the testing process.

• Base plate

  The base plate is around 60 by 60 centimeters. The plate supports the cone and contains the slumped concrete during the test. Most offices manufacture it from steel or wood, giving it a flat and level surface to ensure accurate slump readings are taken.

• Graduated ruler

  It is a ruler of about 1 meter that has clear, readable markings in centimeters. The ruler is placed next to the slumped concrete to determine the amount of slump that has occurred. Rulers are made from sturdy materials like steel to enhance accuracy and durability.

• Suspension system

  A few slump test kits come with a suspension system designed to help balance and lift the cone effortlessly. This system prevents disturbances to the mixture caused by sudden lifting of the cone.

• Material

  The slump cone made of plastic is lightweight and portable, making it easier to move around job sites. Other slump test apparatus includes cones created from steel that are harder and stronger with resistance to deformation.

How to Use

• Prepare the concrete mix

  A slump test is conducted after ensuring the concrete mixture is within the prescribed proportions of water, cement, aggregates, and admixtures. This is to ensure the mixture has the right workability.

• Place the slump cone

  The cone should be positioned on a flat, dry, and non-absorbent surface. The cone should be placed on the base plate and ensure it is secured so it does not slip when the mixture is added.

• Fill the cone

  The slump cone is filled with concrete in three equal layers up to the top rim. Each layer is compacted using a rod to remove air pockets from within the mixture. The first two layers are each rodded 25 times, and the last one is rodded 50 times.

• Lifting the cone

  Once the cone is filled and compacted, the cone is carefully lifted straight up without disturbing the mixture. This is where a suspension system comes in handy.

• Measuring slump

  The slump is measured using a ruler immediately after the cone is lifted. The distance between the top of the initial placed mixture and the top surface of the slumped concrete is the slump value.

Maintenance

• Daily cleaning

  Clean the cone immediately after use before the concrete hardens to prevent cement from accumulating on the cone. Use a wire brush and water to clean it, removing all debris.

• Inspection

  Check for any visible signs of deformation, cracks, or wear each time the test is conducted. Inspect previously used cones to make sure they do not cause inaccurate results.

• Storage

  The cone and base plate are stored in an area that is dry and free from extreme weather conditions. Avoid stacking other materials on top of the cone to prevent bending or deformation.

• Periodic Maintenance

  Check for bends, dents, or signs of deterioration on the cone, like thinning edges. Consider replacing the cone when it gets worn to maintain accuracy. It can be replaced if the cone is exposed to frequent testing or intense environments.

Quality and Safety Considerations of Slump Test Apparatus

Quality considerations

• Materials used

  The cone should be created from high-quality, durable materials that do not easily bend or rust. It can be plastic or reinforced steel. This prevents the cone from warping and altering the results.

• Standard dimensions

  The dimensions should conform to ASTM and EN standards. These regulations are specific about the cone shape, base plate size, and height to make sure the results are correct. Using a cone that is too short or too wide may lead to wrong workability measures.

• Workmanship

  There should not be any visible gaps, seams, or rough edges between the slump cone. They might potentially disturb the mixture, leading to inconsistent results. Proper care is taken while crafting the cone and base plate to ensure they are smooth and even.

• Level surface

  The base plate should be level and flat. An uneven surface may lead to slumping in one direction and provide inaccurate measures. The base plate is placed on a flat, level ground before doing the test to make sure it is steady.

• Proper suspension system maintenance

  It helps balance and lift the cone without disturbing the mixture. Regular inspection and cleaning help avoid rust that may impact its strength.

Safety considerations

• Concrete hazards

  Concrete has the possibility to cause skin irritation if contact is left for a longer time without protection. Safety gloves should be worn when handling concrete to prevent direct contact. It should be allowed to dry completely from clothing or any other surface. Dried concrete is hard to remove and may cause skin irritation.

• Heavy lifting

  The slump cone can weigh a lot and do more lifting without proper techniques and balancing, which may lead to back strains or other injuries. When lifting the cone, always use the legs and keep close to the cone to maintain the center of gravity. Do not twist the body while holding the funnel so as to avoid strain on the lower back.

• Trip hazards

  Ensure the area where the cone is placed is free from wires or other items that may cause tumbling while moving. When carrying the cone, keep the eyes up to accurately see the obstacles.

• Equipment stability

  The cone should remain stable when filled with concrete to prevent toppling over and causing spills or accidents. Place the cone on a level surface and secure the mixture so it does not shift during the testing process.

Q&A

Q1: What is a slump test now done?

A1: It determines the consistency of fresh concrete before pouring. It tests the workability of the concrete mixture to check for variation in proportion during batching.

Q2: What are the parts of the slump test apparatus?

A2: The main parts include the slump cone, base plate, graduated measures, and lifting device. They work together to shape, support, and carefully lift the concrete allowing an accurate measure of the results.

Q3: What are the hazards of slump testing?

A3: Concrete may cause skin irritation if contact is left without proper protection. Handling wet concrete may also be slippery and lead to falls or injury. Moving heavy objects can also cause sprains to the body.

Q4: What causes inaccurate slump measures?

A4: An uneven surface of the base plate and non-standard cone dimensions may cause an error in results. Improper mixing with air pockets within the mixture may also impact the level of measured slumping.