Balance emissions and CO<sub>2</sub> uptake in concrete structures: simulation based on the cement content and type

While the cement plant is considered one of the most polluting industry, responsible for about 5% of global CO₂ emissions, the concrete has the potential to uptake this gas through the carbonation process, offset in part the emissions generated in its production. With the purpose to analyze this process, this study aims to evaluate emissions and CO₂ uptake with cement content 300-580 kg produced with different cement types (CP II F, CP II E, CP II Z, CP III, CP IV and CP V). Through mathematical modeling, the emissions balance was made, identifying the mix that shows good resistance to carbonation and greater absorption of CO₂ during the concrete life cycle. The results show that concrete with cement consumption between 380 and 420 kg/m³ showed better balance emissions.

Keywords:
CO₂ sequestration; cement content; CO₂ emissions; compensatory measures; sustainability

Authorship

E. F. FELIX

Department of Structural Engineering, São Carlos School Engineering, University of São Paulo, São Carlos, SP, Brazil;emerson.felipe.felix@gmail.comUniversity of São PauloBrazilSão Carlos, SP, Brazil Department of Structural Engineering, São Carlos School Engineering, University of São Paulo, São Carlos, SP, Brazil;emerson.felipe.felix@gmail.com

E. POSSAN

Postgraduate Program in Civil Engineering, Federal University of Latin American Integration, Foz do Iguaçu, PR, Brazil. epossan@gmail.comFederal University of Latin American IntegrationBrazilFoz do Iguaçu, PR, Brazil Postgraduate Program in Civil Engineering, Federal University of Latin American Integration, Foz do Iguaçu, PR, Brazil. epossan@gmail.com

SCIMAGO INSTITUTIONS RANKINGS

Figures | Tables

Figures (9)
Tables (6)

Type of cement	Addition		F_cj (MPa)	Dosage (kg/m³)
Type of cement	Type*	Content*	F_cj (MPa)	Cement	Stone	Sand	Water
CP II-E	Slag	6 - 34	20.92	300.00	864.17	1056.21	120.00
			25.55	340.00	860.41	1051.61	136.00
			29.78	380.00	849.14	1037.84	152.00
			31.75	400.00	845.39	1033.25	160.00
			33.63	420.00	841.63	1028.66	168.00
			37.13	460.00	834.12	1019.47	184.00
			40.30	500.00	826.60	1010.29	200.00
			43.20	540.00	819.09	1001.11	216.00
			45.84	580.00	811.57	991.92	232.00
CP II-F	Limestone filler	15 - 50	20.22	300.00	818.24	1000.07	120.00
			24.87	340.00	808.99	988.76	136.00
			29.90	380.00	799.74	977.46	152.00
			32.59	400.00	842.95	1090.77	160.00
			34.48	420.00	790.49	966.15	168.00
			38.66	460.00	781.24	954.85	184.00
			42.46	500.00	771.99	943.54	200.00
			45.93	540.00	762.74	932.24	216.00
			49.10	580.00	753.49	920.94	232.00
CP II-Z	Fly ash	15 - 50	21.98	300.00	926.26	1132.09	120.00
			26.56	340.00	912.73	1115.56	136.00
			30.69	380.00	899.21	1099.04	152.00
			32.24	400.00	795.11	971.81	160.00
			34.39	420.00	885.69	1082.51	168.00
			37.72	460.00	872.16	1065.98	184.00
			40.73	500.00	858.64	1049.45	200.00
			43.45	540.00	845.12	1032.92	216.00
			45.92	580.00	831.60	1016.39	232.00

Variáveis de análise	Concrete
Tipo de cimento	CP II E¹	CP II Z¹	CP II F¹	CP III²	CP IV³	CP V ARI⁴
Compressive strength (MPa)	Variable	Variable	Variable	Variable	Variable	Variable
Addition content (%)	6 - 34	6 - 14	0 - 10	35 - 70	15 - 50	0 - 5
Addition type	Slag	Fly ash	Fly ash	Slag	Fly ash	Limestone filler
Exposure condition ⁵	EP	EP	EP	EP	EP	EP
Relative humidity (%)	70	70	70	70	70	70
CO2 concentration (%)	0.04	0.04	0.04	0.04	0.04	0.04
Time (years)	1 - 100	1 - 100	1 - 100	1 - 100	1 - 100	1 - 100

Emissions/year	2008	2009	2010	2011	2012
Energy use	246.00	224.00	210.00	214.38	210.27
Calcination	368.00	363.00	358.00	364.78	361.10
Transportation	33.00	31.00	31.00	30.66	30.26

(a)
Type of cement	Properties of concrete			Environmental conditions
	Cement	f_c	Addition	CO₂	UR
	k_c	k_fc	k_ad	k_co2	K_ur
CP I	19.80	1.70	0.24	18.00	1300
CP II E	22.48	1.50	0.32	15.50	1300
CP II F	21.68	1.50	0.24	18.00	1100
CP II Z	23.66	1.50	0.32	15.50	1300
CP III	30.50	1.70	0.32	15.50	1300
CP IV	33.27	1.70	0.32	15.50	1000
CP V ARI	19.80	1.70	0.24	18.00	1300

(b)
Exposure conditions of structures
Sheltered from rain	kce
Indoor sheltered from rain	1.30
Outdoor, sheltered from rain	1.00
Outdoor, exposed to rain	0.65

Type of cement	C¹ (kg/m³)	Depth carbonation (mm)
		Structure (As² = 6,5 m²)							Waste particles (post-demolition) (As² = 64±1 m²)
		5	10	20	30	40	50	60	70	75	80	85	90	95	100
CP II Z	300	10	14.3	20.1	24.6	28.4	31.8	34.9	37.5	10	14.5	*	*	*	*
	400	5.6	7.8	11.2	13.6	15.7	17.6	19.2	20.8	5.6	7.76	9.51	10.9	12.2	13.4
	500	3.9	5.6	7.9	9.7	11.2	12.6	13.7	14.9	3.9	5.42	6.64	7.67	8.57	9.39
	580	3.3	4.7	6.6	8.2	9.3	10.5	11.4	12.5	3.3	4.46	5.47	6.31	7.06	7.74
CP II E	300	10.3	14.6	20.6	25.2	29.1	32.6	35.7	38.6	10.3	14.5	*	*	*	*
	400	5.5	7.8	11.0	13.5	15.5	17.4	19.0	20.6	5.5	7.76	9.51	10.9	12.2	13.4
	500	3.8	5.4	7.7	9.4	10.8	12.1	13.3	14.4	3.8	5.42	6.64	7.67	8.57	9.39
	580	3.2	4.5	6.3	7.7	8.9	10.0	10.9	11.8	3.2	4.46	5.47	6.31	7.06	7.74
CP II F	300	11.0	15.5	21.9	26.8	31.0	34.6	37.9	41.0	11.0	*	*	*	*	*
	400	5.4	7.6	10.8	13.2	15.3	17.1	18.7	20.2	5.4	7.62	9.34	10.7	12.0	13.2
	500	3.6	5.0	7.1	8.7	10.0	11.2	12.3	13.3	3.6	5.02	6.14	7.10	7.93	8.69
	580	2.8	4.0	5.7	7.0	8.1	9.0	9.9	10.7	2.8	4.02	4.93	5.69	6.36	6.97
CP III	300	15.4	21.8	30.9	37.8	43.7	48.8	53.5	57.8	15.4	*	*	*	*	*
	400	7.1	10.1	14.2	17.4	20.1	22.5	24.6	26.6	7.1	10.0	12.3	14.2	*	*
	500	4.0	5.7	8.0	9.8	11.3	12.6	13.9	15.0	4.0	5.65	6.92	7.99	8.94	9.79
	580	2.9	4.2	5.9	7.2	8.3	9.3	10.2	11.0	2.9	4.16	5.10	5.89	6.58	7.21
CP IV	300	11.5	16.2	22.9	28.1	32.5	36.3	39.7	42.9	11.5	*	*	*	*	*
	400	5.6	7.9	11.2	13.8	15.9	17.8	19.5	21.0	5.6	7.94	9.73	11.2	12.5	13.7
	500	3.7	5.3	7.5	9.2	10.6	11.8	12.9	14.0	3.7	5.28	6.47	7.47	8.35	9.15
	580	3.0	4.2	6.0	7.3	8.5	9.5	10.4	11.2	3.0	4.23	5.19	5.99	6.70	7.34
CP V ARI	300	7.3	10.3	14.5	17.8	20.5	23.0	25.2	27.2	7.3	10.2	12.5	14.5	*	*
	400	3.1	4.4	6.3	7.7	8.8	9.9	10.8	11.7	3.1	4.42	5.41	6.25	6.99	7.66
	500	1.9	2.7	3.8	4.6	5.3	6.0	6.5	7.1	1.9	2.67	3.27	3.77	4.22	4.62
	580	1.4	2.0	2.9	3.5	4.0	4.5	5.0	5.4	1.4	2.02	2.47	2.85	3.19	3.50

Type of cement	Addition		F_cj (MPa)	Dosage (kg/m³)
Type of cement	Type*	Content*	F_cj (MPa)	Cement	Stone	Sand	Water
CP III*	Slag	6 - 34	19.64	300.00	875.35	1069.88	120.00
			22.53	340.00	860.82	1052.11	136.00
			28.19	380.00	846.28	1034.34	152.00
			30.92	400.00	839.01	1025.46	160.00
			33.56	420.00	831.74	1016.58	168.00
			38.61	460.00	817.21	998.81	184.00
			43.33	500.00	802.67	981.04	200.00
			47.73	540.00	788.13	963.28	216.00
			51.83	580.00	773.60	945.51	232.00
CP IV**	Fly ash	15 - 50	25.09	300.00	757.21	925.48	120.00
			30.62	340.00	746.04	911.82	136.00
			35.68	380.00	734.86	898.16	152.00
			38.03	400.00	729.27	891.33	160.00
			40.28	420.00	723.68	884.50	168.00
			44.46	460.00	712.50	870.84	184.00
			48.26	500.00	701.32	857.17	200.00
			51.73	540.00	690.15	843.51	216.00
			54.89	580.00	678.97	829.85	232.00
CP V ARI***	Limestone filler	0 - 5	24.01	300.00	785.03	959.48	120.00
			30.26	340.00	774.23	946.28	136.00
			36.32	380.00	763.44	933.09	152.00
			39.25	400.00	758.04	926.49	160.00
			42.10	420.00	752.64	919.89	168.00
			47.57	460.00	741.84	906.70	184.00
			52.70	500.00	731.05	893.50	200.00
			57.51	540.00	720.25	880.30	216.00
			62.02	580.00	709.45	867.11	232.00

Brasil

Brasil

Balance emissions and CO2 uptake in concrete structures: simulation based on the cement content and type

Abstract

Balance emissions and CO₂ uptake in concrete structures: simulation based on the cement content and type