What is Rilem tube test?
RILEM tube tests are used to evaluate the performance of water repellents in the field. There are two types of RILEM tubes, 5.0 mL (tall) tubes and 60 mph (short) tubes. The 5.0 mL tubes are use on brick, natural stone, cast-in-place concrete and precast concrete. The 60 mph tubes are used on Custom Masonry Units.
How do you use a Rilem tube?
RILEM Tube and Test Method Description The large opening of the tube is adhered to the stone’s surface using putty or rope caulk. Water is then added to the tube and monitored over time. As the water drops an absorption rate (volume of water absorbed over time) can be determined.
What is the common test used to determine how fast water passes through or absorbs into soil or other substrates?
The RILEM tube test was adopted in the United States in the early 1980s by the water repellent manufacturing industry to assess water absorption properties of walls and other substrates, with or without treatment.
How is water absorption measured?
It is calculated as the moisture content, which is equal to: (weight of the container with wet soil minus the weight of the container with dry soil) divided by (weight of the container with dry soil minus the weight of the container), then multiplied by 100 to express it as a percentage.
How do you test ground strength?
The CBR test is performed by measuring the pressure required to penetrate a soil sample with a plunger of standard area. The measured pressure is then divided by the pressure required to achieve an equal penetration on a standard crushed rock material. The harder the surface, the higher the CBR value.
What is Cobb test?
Cobb test (sized papers and paperboards) The Cobb test determines the amount of water absorbed into the surface by a sized (non-bibulous) paper, paperboard, and corrugated fibreboard paper or paperboard sample in a set period of time, usually 60 or 180 seconds (Cobb60 or Cobb180). Water absorbency is quoted in g/m2.
What is CBR value of soil?
CBR is the ratio expressed in percentage of force per unit area required to penetrate a soil mass with a standard circular plunger of 50 mm diameter at the rate of 1.25 mm/min to that required for corresponding penetration in a standard material. The ratio is usually determined for penetration of 2.5 and 5 mm .
Why do we do Cobb test?
The Cobb test is essential as it tests the ability of the paper to resist the penetration of water and quantity of water absorbed by the surface of fiberboard. If fiberboard absorbs too much water, the box may have difficulty maintaining strength and integrity.
How do you test water absorption?
For the water absorption test, the specimens are dried in an oven for a specified time and temperature and then placed in a desiccator to cool. Immediately upon cooling the specimens are weighed. The material is then emerged in water at agreed upon conditions, often 23°C for 24 hours or until equilibrium.
How is Cobb test calculated?
To determine the Cobb Value, subtract the weight of the sample before testing from the weight of the sample after testing.
What is Cobb testing?
Cobb test (sized papers and paperboards) The Cobb test determines the amount of water absorbed into the surface by a sized (non-bibulous) paper, paperboard, and corrugated fibreboard paper or paperboard sample in a set period of time, usually 60 or 180 seconds (Cobb60 or Cobb180).
What is the minimum CBR value for subgrade?
The minimum value of CBR for subgrade soils is 6%, although 10% is recommended by subgrade stabilization [5] .
What is CBR and CDR?
PIP: Both the crude birthrate (CBR) and the crude death rate (CDR) represent a simple concept: the number of births or deaths which occur in a given year per 1000 population. They can also be used to calculate another fundamental measure, the rate of natural increase.