UNIQUE SOIL HEARDENING AGENT

The Standard “STEIN” Blending Ratio (Standard SBR)

Ａ．STEIN-R: In the case of building subgrades, add 8% to 12% to the maximum dry density weight of the soil & blend with STEIN.

In the case of building basecourses, add 4% to 10% to the maximum dry density weight of the soil & blend with STEIN.

One experimental case performed by blending

STEIN-R with 1,895 kg maximum dry density weight decomposed granite soil shows the diversity of the CBR rating depending on the SBR.

The CBR rating of that decomposed granite soils is 0.4% without STEIN, 7.6% with 5% SBR, 12% with 7.0% SBR, 25.1% with 10% SBR and

39% with 14% SBR.

 

Ｂ．STEIN-M･･･The SBR 8% to 30% in the same construction cases as STEIN-R

The process in determining the SBR

The determination of the SBR is the most important matter to be considered prior to the actual construction and its process is as follows.

At first, the objective construction strength must be established, considering various construction sites conditions such as temperature,

earth nature, water level, soil nature and so on. Secondly, conduct the room experimentation in order to figure out and determine the standard SBR using a soil samples extracted from the planned construction site. Finally, determine the SBR applying the in-place modification index calculated taking the anticipated change index caused by the actual construction works, strength reduction caused by the difficulty of the water content management and different ways of blending methods into considerations.

 

Necessary precautions to effectively use “STEIN” in the construction works

1.When the rainfall is expected during the construction period, cover the construction spot with water proof sheets to prevent water

  content of the soil from getting excess water. And when excess water evaporation from the constructed objects is expected, cover the   

  constructed parts with sheets in order to keep the optimum water content.

2, When the water content of the soil is not suitable to mix with STEIN, spray water to the soil prior to or after mixing STEIN and well   

  mix the soil with water to attain the optimum water content of the soil.

3, Pay attention to maintain the appropriate water content throughout the construction work.

  Excess water content causes rubber-tire rollers and other construction machines unable to function effectively & to get required rolling    

  compaction. Even if rolling compaction level is achieved, the surface of the construction might not be smooth enough because of adhering  

  and sticking soil to the machines.

4, During the winter period or cold seasons in which the minimum temperature of the day is under 5-degree Celsius, hardening effects

  of STEIN is not expected. Therefore, avoid construction works with STEIN.

5, Even in the construction of public parks, promenades and stabilization works of athletic fields which soft and natural soil color

  feelings are more important than high construction strength and abrasion resistance property, and in the construction of temporary

  roads for another main construction projects and temporary parking lots which base courses are not paved and exposed, determination

  of the SBR is the most important matter, because depending on the soil nature, growth of surface wears and cracks are apt to happen  

  during their use. The various construction examples STEIN are available.

 

Various construction examples on the usage of “STEIN”

1, The construction of upper and lower layers of the general roads which are traditionally constructed by asphalt concrete or cement  

  concrete. The surface asphalt concrete layers are necessary to be placed when certain level of abrasion resistance property is required.

2, The construction of base course of roads or trails such as agricultural, forestry and temporary construction roads. The surface asphalts

concrete layers are necessary to be placed when certain level of abrasion resistance property is required.

3, The light pavement constructions such as public parks, promenade roads in parks, public playgrounds, jogging track, cycling paths

  and walking passes or parking lots of the shrines/temple’s areas with which high construction strength and abrasion resistance property,

  usually required, in general roads are not necessary.

4, The construction of the under base of tennis courts and volleyball courts & also the construction of gate-ball fields and athletic

  courses.

5, The construction of walking paths in the school campus & prevention works of dust clouds and muddiness in public playgrounds.

6, The construction of livestock’s hutch floors, paddocks, barnyard, manure reservoirs, store house floors, agricultural workshops, and

  so on.

7, The construction of fish breeding ponds, water reservoirs, drainage ditches, and the solidification works of water ditch bases.

8, The solidification treatment of muddy sewage dredged up from rivers and oceans.

9, The stabilization treatment of soft grounds and subgrades.

 

The usages and its specifications on the types of “STEIN” products

1, STEIN-R

STEIN-R is standard type of STEIN products and mainly used for the construction works of basecourses and subgrades of roads in "the blending in-place soil method" or "the blending carried-in soil method". In the blending in-place soil method, STEIN-R is placed and spread equally on the designed road surfaces and blended with soils in there by construction machines such as stabilizers.

In the blending carried-in soil method, soil is carried in massively from remote areas to the nearby workshops from roads and blended with STEIN-R. Then those mixed soil are carried again and laid on the road surfaces. The former method is suitable in such conditions which soils existing on the planned roads are suitable for blending with STEIN. If soils on the roads lines are not good in quality to blend with STEIN, the latter method is adapted. Selection of the method should be done taking other various factors on the construction sites into considerations.

In either method, soils must be compacted firmly at the optimum water content state and completed with the final watering works.

2, STEIN-M

STEIN-M is employed as the mortar system, in such areas which the construction sites are on a steep slope or a muddy soft ground and rolling compaction is not available, or the obstacles hinder the construction machines to advance to the site, STEIN-M is blended with soils and used as a workable paste. This is also utilized to solidify burned refusal ashes and industrial waste materials.

3, EC-type

STEIN-EC is produced by utilizing burned refusal ashes and used for the soil improvement agent.