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The California Bearing Ratio (CBR) is a measure of the strength of the subgrade of a road or other paved area, and of the materials used in its construction. The ratio is measured using a standardized penetration test first developed by the California Division of Highways for highway engineering. [1] Empirical tests measure the strength of the ...
ACN-PCN method. The Aircraft Classification Number (ACN) – Pavement Classification Number (PCN) method is a standardized international airport pavement rating system promulgated by the ICAO in 1981. The method has been the official ICAO pavement rating system for pavements intended for aircraft of apron (ramp) mass greater than 5700 kg from ...
R-value (soils) The R-Value test [1] measures the response of a compacted sample of soil or aggregate to a vertically applied pressure under specific conditions. This test is used by Caltrans for pavement design, replacing the California bearing ratio test. Many other agencies have adopted the California pavement design method, and specify R ...
The Proctor compaction test is a laboratory method of experimentally determining the optimal moisture content at which a given soil type will become most dense and achieve its maximum dry density. The test is named in honor of Ralph Roscoe Proctor [ de ] , who in 1933 showed that the dry density of a soil for a given compactive effort depends ...
The test method consists of pushing an instrumented cone, with the tip facing down, into the ground at a controlled rate (controlled between 1.5 -2.5 cm/s accepted). The resolution of the CPT in delineating stratigraphic layers is related to the size of the cone tip, with typical cone tips having a cross-sectional area of either 10 or 15 cm 2 ...
The so-called CBR-value represents the ratio of the percentage of the loads required to press a punch of certain dimensions first into a well compacted sample of soil and then into a standard sample of compacted gravels, to a depth of 0.1 inch. In any case, it is necessary to classify the soil type with reference to the Unified Soil ...
It is a pointed cone attached to a spring-loaded handle by extension spindles. The device is pushed into the ground and a scale reads off the estimated CBR value. It is a quick and simple means of estimating the CBR of the top 0.5 metres of subgrade but is less accurate than the more involved standard CBR test.
The test reports loss of mass to abrasion and impact, expressed as a percentage of initial sample mass. [7] Maximum acceptable loss for the base course of the road is 45%; the more demanding surface course must be 35% or less. [1] The test was developed by the city engineers of Los Angeles in the 1920s. [8]