Liquid Limit Test (Ll)

 

Liquid limit is defined as minimum water content at which the soil flow under the application of a very small shearing force. The LL is usually determined in the laboratory using a mechanical device. Liquid limit is moisture content at which 25 blows in standard liquid limit apparatus will just close a groove of standardized dimensions cut in the sample by the grooving tool by specified amount.

clip_image002 clip_image004

clip_image006 clip_image008

Liquid limit tests

Testing procedure

The dry soil sample that passing 0.425 mm test sieve is mixed with distilled water to a thick paste.

Some of the soil paste is placed in the cup, leveled off horizontally and divided by cutting a groove.

The two halves of the soil gradually flow together as the cup is raised and repeatedly dropped on to the base at the rate of 2 drops per second.

The number of blows required to close the bottom of the groove is calculated.

This test is repeated after adding more water.

All test samples are collected and placed on the oven for 24 hours.

The dry samples are weighed for the moisture content of soil.

From the above reading, the percent of moisture content of the soil is determined and plot the number of blows-moisture content % graph. According to the graph, the LL is defined as the moisture content at which 25 blows.

Comments

Post a Comment

Popular posts from this blog

CRACK TREATMENT OF THE ASPHALT BINDER COURSE

Image
  Main Break Water(MBW) access road occurs several cracks on the asphalt binder course. The road cracks are monitored and investigated with specialist from RDA Research & Development. This report describes the reason and remedial method of the cracks based on the investigation and consultation. MBW access road structure consists of fallowing cross section and the core samples have been taken on the cracks. According to core sample data, can be observed that the crack was started from CBM and reflected to the binder course surface. CRACK INVESTIGATION The crack survey carried out for the entire road and investigation detail summarized as an attached sheet. Core samples were taken from the jointly selected locations with the engineer. MBW access road cracks were categorized into two types based on crack surface appearance. Transverse cracks Longitudinal cracks
Read more

Field Density Test

Image
  The sand cone method is used for field density test in our highway construction. In the field, the dry density test is carried out for check the compaction of layers. Compaction is most useful for the preparation of sub base grade and other pavement layers and in construction of embankment in order to increase the stability and to decrease settlement. In field compaction, the compacting moisture content is first controlled at optimum moisture content and the adequacy of rolling or compaction is controlled by checking the dry density achieved and comparing with the maximum dry density. Base layer-98% Sub base layer-98% Type 1 layer-95% ABC layer-100% Road shoulder- 98% Field density test Testing procedure: The weight of empty sand cone is measured and then filled with dry sand and weighted. The soil excavated from the hole is collected and weighted. After weighting, a specimen of soil is taken to determine it water content. The sand cone is placed on the
Read more