sand_clay_mix_calcs: Calculate soil mixture component weights \loadmathjax

In evanmascitti/soiltestr: Functions for Laboratory Soil Testing

Calculate soil mixture component weights \loadmathjax

Description

Returns a concise, printer-friendly reference sheet. It is useful when mixing two soils ("sand" and "clay") from an air-dry condition to produce a final mixture having a particular % sand-size particles. See Details for more info on the calculations.

Usage

sand_clay_mix_calcs(
  mix_date,
  sample_name = NULL,
  sandy_name,
  clayey_name,
  final_sand_pct,
  final_OD_kg = 35,
  sand_sandy,
  sand_clayey,
  w_sandy,
  w_clayey,
  round = FALSE
)

Arguments

mix_date	Date the mixture is being produced in ISO format (YYYY-MM-DD).
sample_name	Character vector of the unique mix identifiers
sandy_name	Unique name assigned to the particular sand material
clayey_name	Unique name assigned to the particular sand material
final_sand_pct	Numeric vector of final sand contents (decimal form) expt.mix.nums. It corresponds to the final desired % of sand-size particles in the soil mixture on an oven-dry mass basis.
final_OD_kg	desired mass of mixed soil to obtain, on an oven-dry mass basis (in kilograms). Defaults to 35 kg. This is a good estimate of the mass needed to perform a standard Proctor test, a modified Proctor test, and to prepare 3 "cleat-mark" cylinders, with a 10% extra estimate to allow for PSA, Atterberg limits, and a margin for error.
sand_sandy	a numeric vector of length 1 representing the fraction of the "sand" component which is >53 μm sieve diameter, on an oven-dry mass basis (decimal form).
sand_clayey	a numeric vector of length 1 representing the fraction of the "clay" component which is >53 μm sieve diameter, on an oven-dry mass basis (decimal form).
w_sandy	The gravimetric water content of the air-dry "sand" component, in decimal form.
w_clayey	The gravimetric water content of the air-dry "clay" component, in decimal form.
round	Logical, whether to round the component masses. Use only for easier formatting in .Rmd documents as precision is lost when passing to later calculations.
w_final	a numeric vector of the same length as expt_mix_nums (if the mixes are to have different water contents), or a single numeric value (if all mixes are to have the same final water content). Defaults to 0.05 which is the lowest water content typically used in a compaction test.

Details

This function solves a 2-member system of equations, accounting for the hygroscopic water content of each soil and their respective % sand-size particles. The user may choose any desired final % sand, and (so long as the water contents of each soil are known), the final mixture will contain the desired % sand on an oven-dry mass basis.

The equation for the air-dry mass of sandy soil is

\mjdeqn

m_sandy~(air-dry)~=~\fracS_f~-~S_clayeyS_sandy~-~S_clayey~\cdot~(1+w_sandy)~\cdot~m_~total~mixture

and the equation for the air-dry mass of clayey soil is

\mjdeqn

m_clayey~(air-dry)~=~\left\lbrack(1~-~\left(\fracS_f~-~S_clayey S_sandy~-~S_clayey\right)\right\rbrack~\cdot~ (1~+~w_clayey)~\cdot~m_~total~mixture~(oven-dry)

Value

A table of values with an appropriate number of significant figures.

Examples

sand_clay_mix_calcs(
  mix_date = Sys.Date(),
  sample_name = NULL,
  sandy_name = "concrete-sand",
  clayey_name = 'brown-gumbo',
  final_sand_pct = seq(0.2, 0.8, by = 0.2),
  final_OD_kg = 30,
  sand_sandy = 0.97,
  sand_clayey = 0.06,
  w_sand = 0.001,
  w_clay = 0.02)

evanmascitti/soiltestr documentation built on Oct. 6, 2022, 5:32 p.m.