Renewable biomass-derived lignin in transportation infrastructure strengthening applications

Figures & data

Table 1 Summary of Iowa class 10 soil engineering properties.

Property	Class 10
Gravel (%)	7.6
Sand (%)	40.4
Silt and clay (%)	51.9
Liquid limit (%)	39.3
Plasticity limit (%)	16.0
Plasticity index (%)	23.3
USCS group symbol	CL
USCS group name	Sandy lean clay
AASHTO (group index)	A-6(8)
Optimum moisture content (%)	17.7
Maximum dry unit weight (kg/m^3) pound per cubic foot, pcf	1693 (105.7)

Table 2 Component materials in BioOil.

Components	Percent by weight
Gases	5–10
Water	Up to 25
Lignin	25
Char	4
Aldehydes	35–41

Table 3 Chemical composition of Ottumwa fly ash.

Components	Percent by weight
Na2O	3.21
MgO	6.81
Al2O3	16.2
SiO2	31.6
P2O5	1.02
SO3	3.13
K2O	0.32
CaO	28.8
TiO2	1.24
Fe2O3	6.03
SrO	0.51
Mn2O3	0.02
BaO	0.89
Loss on ignition (LOI)	0.30

Table 4 Primary treatment group combinations.

		Additives (%)^a
Moisture content level	Curing period (day)	BioOil	Fly ash
Without water	1	13.7^b, 17.7^b, 21.7^b	N/A^c
	7	13.7^b, 17.7^b, 21.7^b	N/A^c
OMC − 4	1	0, 1, 3, 6, 12, 15	0, 1, 3, 6, 12, 15
	7	0, 1, 3, 6, 12, 15	0, 1, 3, 6, 12, 15
OMC	1	0, 1, 3, 6, 12, 15	0, 1, 3, 6, 12, 15
	7	0, 1, 3, 6, 12, 15	0, 1, 3, 6, 12, 15
OMC+4	1	0, 1, 3, 6, 12, 15	0, 1, 3, 6, 12, 15
	7	0, 1, 3, 6, 12, 15	0, 1, 3, 6, 12, 15

a Numbers indicate per cent of additive added by dry soil weight.

b Same water contents as OMC, OMC+4 and OMC − 4 of untreated soil.

c Not available.

Figure 1 Effect of mixing procedures on UCS.

Figure 2 Prepared samples for USC test.

Table 5 Average dry density of compacted samples (unit: kg/m³).

Moisture content level			OMC − 4		OMC		OMC+4
Curing period			1 day	7 days	1 day	7 days	1 day	7 days
Type	Untreated soil		1625	1628	1627	1636	1653	1642
	BioOil (raw)		1620	1618	1620	1622	1637	1627
	BioOil (evap.)	1%	1630	1630	1624	1631	1641	1645
		3%	1615	1621	1629	1627	1629	1633
		6%	1622	1617	1623	1615	1606	1611
		12%	1613	1621	1574	1604	1549	1571
		15%	1614	1625	1529	1576	1538	1549
	Fly ash	1%	1642	1635	1655	1649	1647	1641
		3%	1633	1635	1653	1641	1646	1650
		6%	1628	1626	1639	1635	1637	1638
		12%	1625	1621	1618	1614	1610	1609
		15%	1625	1627	1618	1625	1611	1611

Table 6 Average wet density of compacted samples (unit: kg/m³).

Moisture content level			OMC − 4		OMC		OMC+4
Curing period			1 day	7 days	1 day	7 days	1 day	7 days
Type	Untreated soil		1831	1831	1898	1904	1972	1967
	BioOil (raw)		1829	2147	1897	1890	1981	1963
	BioOil (evap.)	1%	1848	1837	1905	1929	1975	1982
		3%	1854	1860	1931	1928	1997	1996
		6%	1900	1892	1965	1955	1985	1986
		12%	1954	1957	1961	1999	1933	1964
		15%	1942	1974	1905	1977	1912	1938
	Fly Ash	1%	1864	1933	1940	1883	1997	2055
		3%	1881	1874	1959	1935	2036	2027
		6%	1826	1810	1905	1898	1964	1968
		12%	2040	2002	2050	2027	2076	2093
		15%	2064	2039	2110	2105	2107	2095

Figure 3 Effect of additive types and contents on UCS under OMC − 4 condition.

Figure 4 Effect of additive types and contents on UCS under OMC condition.

Figure 5 Effect of additive types and contents on UCS under OMC+4 condition.

Table 7 Multiple comparison test results.

		p-value^a
Type	Mean	Fly ash	BioOil (raw)	BioOil (evap.)	Soil	Level^b
Fly ash	536.8		0.9922	0.0073	0.0017	A
BioOil (raw)	510.7	0.9922		0.3782	0.0432	A B
BioOil (evap.)	362.0	0.0073	0.3782		0.267	B C
Soil	193.2	0.0017	0.0432	0.267		C

a Italic value indicates p-value is less than 0.5, which means significant difference in a pair of comparisons.

b Levels not connected by the same letter are significantly different.