Features of the hot recycling method used to repair asphalt concrete pavements

Figures & Tables

Indicators	Mesh size (mm)

	20	15	10	5	2.5	1.25	0.63	0.315	0.16	0.071
Partial residuals (g)	32	8	88	160	120	52	100	140	116	52
Partial residuals (%)	3.40	0.85	9.36	17.0	12.7	5.53	10.6	14.8	12.3	5.53
Full passes (%)	96.6	75.7	66.3	49.3	36.3	21.0	20.4	5.5	3.2	0.67
Requirements according to standards	90–100	85–100	75–100	60–70	48–60	37–50	28–40	20–30	13–20	8–14

No.	Indicator names	Actual indicators	DSTU B V.2.3-39 requirements
1	Content of crushed grains by weight (not less %)	85	85
2	Content of lamellar (flaky) and needle-shaped grains by weight (no more %)	15	15
3	Content of grains of weak rocks by weight (no more %)	2.8	5
4	Content of dust and clay particles by weight (no more %)	1	2
5	Clay content in lumps (% by weight, no more)	None	0.25
6	Crushing grade (not less)	1,000	1,000
7	Attrition grade	A1	A1
8	Frost resistance grade (not lower)	F150	F150
9	Plasticity grade	Pl1	Pl1–Pl2
10	Water resistance grade	B1	B1–B2
11	Bulk density ρ_n (kg/m³)	1,318	-

Indicator	Temperature of preparation (°C)

	Granular asphalt concrete with fiber				Granular asphalt concrete

	140	145	150	155	140	145	150	155
Compressive strength (MPa):
at 0°C, R⁰	8.07	8.64	8.35	8.21	7.59	8.2	7.89	7.76
at 20°C, R₂₀	4.3	4.71	4.55	4.42	3.37	3.78	3.62	3.53
at 50°C, R₅₀	1.7	1.9	1.83	1.79	1.04	1.19	1.85	1.82
Water resistance (k_w)	0.89	0.96	0.93	0.92	0.8	0.87	0.84	0.84
Water resistance during long-term water saturation (k_ws)	0.81	0.87	0.84	0.82	0.74	0.8	0.7	0.76
Water saturation (W, % by volume)	2.28	2.2	2.16	2.1	2.68	2.72	2.97	2.99

Condition of the pavement before restoration	Methods of restoration

	1. Hot regeneration with surface treatment	2. Traditional, leveling course (3 cm) and new pavement (6 cm)

Indicators	First option		Second option

	Granular asphalt concrete with fiber	Granular asphalt concrete	Granular asphalt concrete with fiber	Granular asphalt concrete
Compressive strength (MPa):
at 0°C, R⁰	4.52	4.01	4.54	4.07
at 20°C, R₂₀	1.65	1.37	1.7	1.40
at 50°C, R₅₀
Water resistance (k_w)	0.96	0.83	0.94	0.84
Water resistance at long-term water saturation (k_ws)	0.84	0.72	0.8	0.70
Water saturation (W, % by volume)	2.1	2.41	2.35	2.4

No.	Indicator name, unit of measurement	Additive content in bitumen (%)	BND 60/90	Fiber
1	Needle penetration depth (0.1 mm)
	at 25°C	0	76	-
	at 0°C		23
		2	-	47.0
				23.4
		3	-	40.2
				25.8
		4	-	37.4
				25.3
		5	-	36.3
				23.3
2	Ring-and-ball softening point (°C)	0	50	-
		2	-	64
		4	-	67
		5	-	75
		7	-	78
3	Elongation (cm)
	at 25°C	0	100	-
	at 0°C		4.2
		2	-	43.3
				3.5
		4	-	30.5
				4.0
		5	-	27.2
				4.2
		7		5.3
				3.6
4	Brittleness point (°C)	0	−17	-
		2	-	−18
		4	-	−25
		5	-	−22
		7	-	−19

Mixture components	Amount (%)
Granular asphalt	69.75
New crushed stone	30.22
Fiber of fly ash from TPP in China	4.0
Bitumen BND 60/90	3.0

No.	Indicator name, unit of measurement	Test result	DSTU 4044 value for BND 60/90 grade
1	Needle penetration depth (0.1 mm)
	at 25°C	76	From 61 to 90
	at 0°C	23	Not less than 20
2	Ring-and-ball softening point (°C)	50	Not lower 47
3	Elongation (cm)
	at 25°C	100	Not less than 55
	at 0°C	4.5	Not less than 3.5
4	Brittleness point (°C)	−17	Not higher than −15
5	Flash point (°C)	240	Not lower than 230
6	Change in softening point after progress (°C)	3.5	Not more 5
7	Penetration index	−0.2	−1 to +1

No.	Indicator names	Actual indicators	DSTU B V.2.3-39 requirements
1	True density (kg/m³)	2,628	-
2	Average density (kg/m³)	2,621	-
3	Bulk density (kg/m³)	1,540	-
4	Content of dust and clay particles, by weight (no more %)	0.96	2
5	Crushing grade (not less)	1,000	1,000
6	Attrition grade	A1	A1
7	Frost resistance grade (not lower)	F150	F150

Needle penetration depth, 0.1 mm, at 25°C	Temperature (°C)

	When unloading	When laying, not less
40–60 incl.	150–160	140
60–90 incl.	145–150	145