Evaluating the creep behaviour of plastic-processed aggregate-based concrete

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Parameters of the creep coefficient in different models_

Type of model
AASHTO LRFD (2007) [39]	ACI 209.2R-08 [40]
B = ( 61 − 0.58 f c ′ ) B=(61-0.58\hspace{.25em}fc^{\prime} )	B = 10 B=10
d = 1 d=1	d = 0.6 d=0.6
λ = 1.9 \lambda =1.9	λ = 2.35 \lambda =2.35
γ c = k v s k h k f t o − 0.118 {\gamma }_{c}={k}_{vs}{k}_{h}{k}_{f}{t}_{\text{o}}^{-0.118}	γ c = γ l a γ H γ v s γ s γ ρ γ α {\gamma }_{c}={\gamma }_{la}{\gamma }_{H}{\gamma }_{vs}{\gamma }_{s}{\gamma }_{\rho }{\gamma }_{\alpha }
K v s = 1.45 − 0.0051 ( v / s ) {K}_{vs}\hspace{.25em}=\hspace{.25em}1.45\hspace{.25em}-\hspace{.25em}0.0051(v/s) ≥ 1.0	γ l a = 1.25 ( t o ) − 0.118 {\gamma }_{la}=1.25{({t}_{o})}^{-0.118}
K h = 1.56 − 0.008 RH {K}_{h}\hspace{.25em}=\hspace{.25em}1.56\hspace{.25em}-\hspace{.25em}0.008\text{RH}	γ H = 1.27 − 0.0067 RH {\gamma }_{H}=1.27-0.0067\text{RH}
k f = 35 7 + f c ′ {k}_{f}=\frac{35}{7+fc^{\prime} }	γ v s = 2 / 3 1 + 1.13 · e − .0213 v s {\gamma }_{vs}=2/3\left[1+1.13\cdot {\text{e}}^{-.0213\left(\frac{v}{s}\right)}\right]
	γ s = 0.82 + 0.00264 ( S l ) {\gamma }_{s}=0.82+0.00264({S}_{l})
	γ ρ = 0.88 + 0.0024 ( ρ a ) {\gamma }_{\rho }=0.88+0.0024({\rho }_{a})
	γ α = 0.46 + 0.09 α {\gamma }_{\alpha }=0.46+0.09\alpha

Coefficient of correlation of the proposed model for the creep coefficient of PPAC mixes_

Concrete type	Coefficient of correlation (equation (2))
PPAC25	0.98
PPAC50	0.96
PPAC75	0.97
PPAC100	0.97

Calculations for calibrating the ACI models for PPAC mixes_

Model type	Parameter	Concrete type
		PPAC25	PPAC50	PPAC75	PPAC100
ACI 209.2R-08	γ l a {\gamma }_{la}	0.844	0.844	0.844	0.844
	γ H {\gamma }_{H}	1.015	1.015	1.015	1.015
	γ v s {\gamma }_{vs}	1.158	1.158	1.158	1.158
	γ s {\gamma }_{s}	1.189	1.268	1.282	1.321
	γ ρ {\gamma }_{\rho }	0.88	0.88	0.88	0.88
	γ α {\gamma }_{\alpha }	0.73	0.73	0.73	0.73
	γ c {\gamma }_{c}	0.759	0.810	0.819	0.844
	C u {C}_{u}	3.30	2.83	3.50	2.40
	λ PA = C u / γ c {\lambda }_{\text{PA}}={C}_{u}/{\gamma }_{c}	4.35	3.49	4.27	2.84

Mix proportions for concrete mixes used in the current study_

Concrete series	W/C	Total water	Free water	Cement	Fine aggregate	Coarse aggregate
						PPA	CNA
	kg/m3
CN	0.50	240.3	225	450	880	—	688
PPAC25		239			847	141	516
PPAC50		237.6			815	282	344
PPAC75		236.2			782	423	172
PPAC100		234.8			750	565	—

Major mechanical properties for all the concrete series

Sample	Dry density (kg/m3)	Compressive strength (MPa)	Tensile strength (MPa)	Flexural strength (MPa)	Modulus of elasticity (GPa)	Poisson ratio	Abrasion-weight loss (g)
CN	2,183	41.8	3.58	5.42	27.82	0.25	0.40
PPAC25	2,086	35.3	3.32	5.24	20.58	0.28	0.60
PPAC50	1,995	31.7	2.42	5.04	15.06	0.38	0.61
PPAC75	1,896	30.4	2.36	4.47	10.66	0.39	0.63
PPAC100	1,777	30.2	2.25	3.99	10.14	0.39	0.66

Regression analysis results of the PPAC mixes_

Model type	Parameter	Concrete type
		PPAC25	PPAC50	PPAC75	PPAC100
Best fit	B	17.72	26.45	12.71	12.46
	D	0.77	0.92	0.76	0.77
	C u	3.04	2.42	3.03	2.05
	R 2	0.98	0.96	0.98	0.98
AASHTO (2007)	B	40.52	42.60	43.36	43.47
	D	1
	C u	2.84	2.47	3.06	2.09
	R 2	0.97	0.96	0.93	0.92
ACI 209.2R-08	B	10
	D	0.6
	C u	3.30	2.83	3.50	2.40
	R 2	0.97	0.94	0.96	0.96

Aggregate properties used in the current study_

Test	Experimental values		Standard used
	CNA	PPA
Fineness modulus	5.83	5.67	ASTM C136/C136M-14 [26]
Unit weight (kg/m3)	1,554	1,132	ASTM C29/C29M-16 [27]
Voids (%)	37.79	37.44	ASTM C29/C29M-16 [27]
Specific gravity	2.59	1.81	ASTM C127-15 [28]
Water absorption (%)	1.48	0.95	ASTM C127-15 [28]