2. Materials and methods

#### 2.1. Materials and mix design

The cement in this study was CEM I/42.5 R according to TS EN 197-1 [29]. Fly ash (FA) was used to increase the resistance against ASR and supply utilization by recycling this waste material. CRTS obtained by recycling computer screens was provided from Exitcom Corp. in Turkey. The chemical and physical properties of the cement, FA, and CRTS used in this study are provided in Table 1. A superplasticizer was also added to ensure concrete workability.

Four different types and sizes of aggregate were used: river sand (0–3 mm), crushed sand (0– 4 mm), coarse aggregate 1 (5–12 mm), and coarse aggregate 2 (12–20 mm). The coarse aggregates consisted of crushed stone and their maximum size was 20 mm. Figure 1 shows river sand, crushed sand, and CRTS. The gradation curves for CRTS and the other fine aggregates are shown in Figure 2.

Five different mix designs were investigated, as shown in Table 2. These mix designs contained CRTS in the amounts of 0, 5, 10, 15, and 20% by weight of total aggregate crushed sand replacements. After the workability of fresh concrete was determined for each mix, five cubes of size 150150150 mm, five beams of size 100100400 mm, five cylinders of 150 mm in diameter and 300 mm in length, five cubes of size 717171 mm, and five prisms of size 2525285 mm were cast to determine the compressive strength, flexural strength and pulse velocity, elastic modulus, abrasion, and ASR, respectively.

#### 2.2. Test methods

Workability. The slump of fresh concrete was measured using the standard slump test apparatus according to ASTM C143 [30].

Densities and water absorption. Dry, saturated densities and water absorption of hardened concrete were measured according to ASTM C642 [31].

Compressive strength. The compressive strength of the hardened concrete was determined according to ASTM 39 [32] at the ages of 3, 7, 28, and 90 days for the cube specimens of 150150150 mm in size. These cubes were removed from the molds after 1 day and cured in water at 21C before testing.

Flexural strength. The flexural strength of the hardened concrete was determined at the ages of 3, 7, 28, and 90 days for the beams of 100100400 mm in size. These beams were removed from the molds after 1 day and cured in water at 21C before testing. The flexural strength was

Chemical properties Physical and mechanical properties

SiO2 20.5 50.2 50.9 Specific gravity (g/cm<sup>3</sup>

Table 1. Chemical composition and physical properties of cement, fly ash and CRTS.

Figure 1. Photographs of CRTS, crushed sand, and river sand used in the study.

Al2O3 4.65 12.7 2.62 Blaine (m2

BaO — — 9.10 Sb2O3 — — 0.31 ZrO2 — — 0.91 SrO — — 5.97 TiO — — 0.39 CeO2 — — 0.25 Cl 0.01 — — Insoluble residue 0.60 — — Ignition loss 2.15 0.54 —

Constituent (%) Cement Fly ash CRTS Properties Cement Fly ash CRTS

Research on Strength, Alkali-Silica Reaction and Abrasion Resistance of Concrete with Cathode Ray Tube Glass…

Fe2O3 3.40 9.00 0.12 Mass stability (mm) 2.00 — — CaO 62.7 12.53 1.54 Setting period start (min) 153 — — Free CaO 1.09 — — Setting period stop (min) 188 — — MgO 1.02 4.33 0.64 90 μ sieve (%) 0.20 — — SO3 2.21 0.39 — 45 μ sieve (%) 12.8 — — Na2O 0.18 2.75 3.60 2 day-strength (MPa) 30.2 — — K2O 0.41 2.50 4.30 7-day strength (MPa) 51.1 — — PbO — — 0.29 28-day strength (MPa) 62.2 — —

) 3.12 2.04 2.70

http://dx.doi.org/10.5772/intechopen.73873

135

/kg) 360 212 —

Research on Strength, Alkali-Silica Reaction and Abrasion Resistance of Concrete with Cathode Ray Tube Glass… http://dx.doi.org/10.5772/intechopen.73873 135


Table 1. Chemical composition and physical properties of cement, fly ash and CRTS.

The present study investigated the effects of substituting various amounts of CRT glass for fine aggregates in concrete on the following physical, mechanical, and durability properties: unit weight, workability, water absorption, compressive and flexural strength, ultrasonic pulse velocity, static and dynamic elastic moduli, abrasion, and ASR expansion. The crushed sand replacement by cathode ray tube glass sand (CRTS) constituted 5, 10, 15, and 20% by weight of

134 Sustainable Buildings - Interaction Between a Holistic Conceptual Act and Materials Properties

The cement in this study was CEM I/42.5 R according to TS EN 197-1 [29]. Fly ash (FA) was used to increase the resistance against ASR and supply utilization by recycling this waste material. CRTS obtained by recycling computer screens was provided from Exitcom Corp. in Turkey. The chemical and physical properties of the cement, FA, and CRTS used in this study are provided in Table 1. A superplasticizer was also added to ensure concrete workability.

Four different types and sizes of aggregate were used: river sand (0–3 mm), crushed sand (0– 4 mm), coarse aggregate 1 (5–12 mm), and coarse aggregate 2 (12–20 mm). The coarse aggregates consisted of crushed stone and their maximum size was 20 mm. Figure 1 shows river sand, crushed sand, and CRTS. The gradation curves for CRTS and the other fine aggregates

Five different mix designs were investigated, as shown in Table 2. These mix designs contained CRTS in the amounts of 0, 5, 10, 15, and 20% by weight of total aggregate crushed sand replacements. After the workability of fresh concrete was determined for each mix, five cubes of size 150150150 mm, five beams of size 100100400 mm, five cylinders of 150 mm in diameter and 300 mm in length, five cubes of size 717171 mm, and five prisms of size 2525285 mm were cast to determine the compressive strength, flexural strength and pulse

Workability. The slump of fresh concrete was measured using the standard slump test appa-

Densities and water absorption. Dry, saturated densities and water absorption of hardened

Compressive strength. The compressive strength of the hardened concrete was determined according to ASTM 39 [32] at the ages of 3, 7, 28, and 90 days for the cube specimens of 150150150 mm in size. These cubes were removed from the molds after 1 day and cured

velocity, elastic modulus, abrasion, and ASR, respectively.

concrete were measured according to ASTM C642 [31].

the total aggregate.

2. Materials and methods

2.1. Materials and mix design

are shown in Figure 2.

2.2. Test methods

ratus according to ASTM C143 [30].

in water at 21C before testing.

Figure 1. Photographs of CRTS, crushed sand, and river sand used in the study.

Flexural strength. The flexural strength of the hardened concrete was determined at the ages of 3, 7, 28, and 90 days for the beams of 100100400 mm in size. These beams were removed from the molds after 1 day and cured in water at 21C before testing. The flexural strength was

determined using three-point bending tests according to ASTM C78 [33] with an effective span

Research on Strength, Alkali-Silica Reaction and Abrasion Resistance of Concrete with Cathode Ray Tube Glass…

http://dx.doi.org/10.5772/intechopen.73873

Ultrasonic pulse velocity. The ultrasonic pulse velocity of the hardened concrete was determined by selecting a measurement distance of 400 mm at the ages of 3, 7, 28, and 90 days on the 100�100�400 mm beams. The measurements were performed according to ASTM C597

Static and dynamic elastic moduli. The static elastic modulus was determined on 150�300 mm cylinders at the age of 28 days in compression according to ASTM C469 [35]. The dynamic elastic modulus was determined using the 28-day data that were obtained from the ultrasonic pulse velocity of the beams according to ASTM C597, formula obtained from ASTM C597 was used to calculate the dynamic elastic modulus. The formula of dynamic elastic modulus was

> ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi E 1ð Þ � μ r ð Þ 1 þ μ ð Þ 1 � 2μ

Alkali-silica reaction. ASR was determined on the mortar bars of 25�25�285 mm according

Abrasion. The amount of horizontal surface abrasion was determined on the cubes of 71�71�71 mm using the Bohme testing method according to BS EN 13892–3 [37] after 28 days.

The workability was negatively affected with increasing CRTS content, as shown in Table 2. The slump value slightly decreased when the CRTS content increased by 5%. However, the slump decreased by only 2.75 cm when the CRTS content increased to 20%. According to Ling and Poon, fine particle size glass increases water absorption [38]. Similar to these results, Topcu and Canbaz reported that increasing glass content reduced the workability but the reduction was insignificant [15]. Concrete with glass requires more water to achieve the same workability [5, 21]. Ismail and Al-Hashmi, Kou and Xing, and Shayan and Xu, also reported

Table 3 indicates that up to 15% CRTS content in concrete increases the density of hardened concrete in comparison to plain concrete. However, glass content above 15% decreases the density [23]. Changing the glass content from 15 to 20% produces the largest increase in water absorption, which suggests that glass content above 15% leads to higher porosity than specimens without CRTS. The study by Shayan and Xu also indicates that the density decreases

(1)

137

V ¼

s

of 300 mm.

showed in Eq. (1).

to ASTM C1260 [36].

3.1. Workability

[34] before the flexural strength tests.

3. Experimental studies and discussion

3.2. Unit weight and water absorption

that glass added to concrete decreases the workability [2, 15, 16].

Figure 2. Particle size distributions of fine aggregates.


Table 2. Concrete mix designs.

determined using three-point bending tests according to ASTM C78 [33] with an effective span of 300 mm.

Ultrasonic pulse velocity. The ultrasonic pulse velocity of the hardened concrete was determined by selecting a measurement distance of 400 mm at the ages of 3, 7, 28, and 90 days on the 100�100�400 mm beams. The measurements were performed according to ASTM C597 [34] before the flexural strength tests.

Static and dynamic elastic moduli. The static elastic modulus was determined on 150�300 mm cylinders at the age of 28 days in compression according to ASTM C469 [35]. The dynamic elastic modulus was determined using the 28-day data that were obtained from the ultrasonic pulse velocity of the beams according to ASTM C597, formula obtained from ASTM C597 was used to calculate the dynamic elastic modulus. The formula of dynamic elastic modulus was showed in Eq. (1).

$$\mathbf{V} = \sqrt{\frac{\mathbf{E}\left(1-\mu\right)}{\mathbf{\rho}\left(1+\mu\right)(1-2\mu)}}\tag{1}$$

Alkali-silica reaction. ASR was determined on the mortar bars of 25�25�285 mm according to ASTM C1260 [36].

Abrasion. The amount of horizontal surface abrasion was determined on the cubes of 71�71�71 mm using the Bohme testing method according to BS EN 13892–3 [37] after 28 days.
