Residential long-span timber floor typologies: a comprehensive performance assessment and opportunities for value adding to plantation hardwood

Figures & data

Table 1. Bending characteristics of fibre-managed plantation hardwood in the literature.

Timber variety	Age (yrs)	Source	Purpose	MC (%)	Density (kg/m^3)	MoR (MPa)	MoE (GPa)	Citation
E. nitens	16	Tasmania, Australia	Fibre-managed	9.0	526	53.0	10.4	Derikvand 2019
E. globulus	26	Tasmania, Australia	Fibre-managed	10.9	498	47.8	11.8	Derikvand et al. 2020
E. nitens	19	Ñuble, Chile	Fibre-managed	14.4	571	NA	11.5	Opazo-Vega et al. 2021
E. nitens	20	Florentine, Tasmania, Australia	Fibre-managed	8.0	569	NA	13.6	Vega et al. 2020

Table 2. Bending characteristics of solid wood plantation hardwood in the literature.

Timber variety	Age (yrs)	Source	Purpose	MC (%)	Density (kg/m^3)	MoR (MPa)	MoE (GPa)	Citation
E. globulus	10	Scott River	Solid wood	8.0	590	NA	14.1	Downes et al. 2014
E. globulus	10	Wellstead	Solid wood	8.0	621	NA	14.3	Downes et al. 2014
E. globulus	10	Boyup Brook	Solid wood	8.0	648	NA	13.7	Downes et al. 2014
E. globulus	20	Victoria, Australia	Solid wood	12.0	783	NA	18.6	Wentzel-Vietheer et al. 2013
E. nitens	15	Tasmania, Australia	Solid wood	8.0	633	NA	13.8	Medhurst et al. 2012
E. nitens	20	Strathblane, Tasmania, Australia	Solid wood	8.0	615	NA	14.7	Vega et al. 2020
E. nitens	22	Geevston, Tasmania, Australia	Solid wood	8.0	613	NA	13.9	Vega et al. 2020

Table 3. EWP and CMTP floor system typologies.

Typology	Short-hand	Example manufacturer,product, and timber variety	Assumed MoE/MoR (GPa/MPa)	Density (kg/m^3)	Comparable systems	Cross-section	Product image
Dowel-laminated timber slab	DLT slab	StructureCraft DLT-1000 Sitka spruce	10.0/6	480	Nail laminated timber (NLT), glue laminated timber (GLT), cross laminated timber (CLT
Laminated veneer lumber cassette	LVL cassette	Metsawood Kerto-Ripa Kerto Q – panels Kerto S – ribs Spruce	Panels: 10.5/36 Ribs: 13.8/44	Panels: 510 Ribs: 510	Solid timber cassette, composite CLT decks with LVL ribs
Cross-laminated timber on glued- laminated timber ribs	CLT + GLT Ts	KLH KLH-3s CLT: Grade C24 GLT: GL28c	Panels: 11.0/24 Ribs: 12.5/28	Panels: 420 Ribs: 420	CLT slab on GLT ribs, CLT slab on solid timber ribs
Transverse cross-laminated timber slab on glued- laminated timber beams	CLT on GLT beams	CLT slab by XLam and GLT beams by VicAsh XL3 (radiata pine) and GL24h	CLT: 11.0/24 GLT: 11.5/24	CLT: 480 GLT: 480	Transverse CLT slab on LVL beams

Figure 1. Failure mechanisms: (a) compression fibre crushing, (b) along-grain splitting on tension side, and (c) sudden tensile fibre rupture.

Table 4. Material characteristics, MoE and MoR.

		No.	MoE (GPa)	MoR (MPa)	Density (kg/m^3)	Moisture content (%)	Failure mechanism
							Comp.	Tens.	Rupt.
E. globulus	Mean	57	15.4	133.4	893.0	11.4	30	26	1
	CoV		19%	10%	5%	7%	52.6%	45.6%	1.8%
	Characteristic		14.8	109.1
E. nitens	Mean	30	13.9	79.8	576.6	12.0	19	9	2
	CoV		18%	21%	9%	6%	63.3%	30.0%	6.7%
	Characteristic		13.6	51.3

Figure 2. Cumulative density functions of: (a) E. globulus and E. nitens MoR with characteristic 5th-percentile, (b) E. globulus and E. nitens MoE with characteristic 50th-percentile.

Table 5. Results.

Typology cross-section
Typology description		Dowel laminated timber slab			Laminated veneer lumber cassette			Cross laminated timber on glue laminated timber ribs			Transverse cross laminated timber slab on glue laminated timber beams
Short-hand		DLT slab			LVL cassette			CLT + GLT Ts			CLT on GLT beams
Timber variety		SPF	Glob.	Nit.	SPF	Glob.	Nit.	SPF	Glob.	Nit.	SPF	Glob.	Nit.
Deflection utilisation	(%)	100%	90%	77%	100%	78%	77%	99%	99%	89%	99%	97%	88%
Depth	(mm)	230	230	230	250	250	250	280	280	280	390	390	390
Flange thickness	(mm)				23	23	23	110	110	110	110	110	110
Rib width	(mm)				25	25	25	140	140	140	280	280	280
Rib spacing	(mm)				500	500	500	600	600	600	3000	3000	3000
Mass	(kg/m^2)	115	205	133	29	50	32	72	134	86	65	122	78
Response factor		84	53	63	166	109	130	110	76	91	115	79	95
Natural frequency	(Hz)	7.3	6.7	8.0	11.8	10.7	12.8	8.4	7.0	8.4	8.7	7.3	8.7
GWP – Emissions	(kgCO2e)	304	1093	706	210	367	237	436	1126	727	381	1024	661
GWP – Sequestration	(kgCO2e)	−1503	−2727	−1761	−374	−655	−423	−944	−1774	−1145	−858	−1613	−1042
Total GWP	(kgCO2e)	−1199	−1634	−1055	−164	−287	−186	−508	−647	−418	−477	−589	−380
Fire response	(min)	105	367	267	3	8	3	65	116	83	76	157	98

Figure 3. Long-term deflection serviceability limit state utilisation.

Figure 4. System performance comparison.

Derikvand, M., et al., 2019b. Characterisation of physical and mechanical properties of unthinned and unpruned plantation-grown Eucalyptus nitens H. Deane & Maiden lumber. Forests, 10 (2), Article 2. https://doi.org/10.3390/f10020194

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Vega, M., et al., 2020. Radial variation in modulus of elasticity, microfibril angle and wood density of veneer logs from plantation-grown Eucalyptus nitens. Annals of Forest Science, 77 (3), 65. https://doi.org/10.1007/s13595-020-00961-1.

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