Ultrasonic pulse velocity for determining the early age properties of dry-cast concrete containing ground granulated blast-furnace slag

2007 ◽  
Vol 34 (5) ◽  
pp. 682-685 ◽  
Author(s):  
D K Panesar ◽  
S E Chidiac
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Blast Furnace Slag ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Early Age ◽  
Granulated Blast Furnace Slag ◽  
Cast Concrete ◽  
Furnace Slag

This study evaluates the potential use of ultrasonic pulse velocity (UPV) for determining the early age compressive strength of dry-cast concrete containing varying percentages of ground granulated blast-furnace slag (GGBFS). The proposed approach includes computing the dynamic elastic modulus from UPV measurements, evaluating the static elastic modulus from experimentally measured dynamic-to-static elastic modulus ratios, and determining the compressive strength from the static elastic modulus using formulae suggested in ACI-363. The early age strengths of dry-cast concrete containing varying amount of GGBFS, which are determined using UPV measurements, are in good agreement with the measured strength. The evaluation is also extended to include five datasets reported in published literature for concrete containing varying types and amounts of mineral admixtures. Key words: concrete, compressive strength, dry cast, early age properties, ground granulated blast-furnace slag (GGBFS), ultrasonic pulse velocity (UPV).

scholarly journals The Hydration, Mechanical, Autogenous Shrinkage, Durability, and Sustainability Properties of Cement–Limestone–Slag Ternary Composites

2021 ◽  
Vol 13 (4) ◽  
pp. 1881
Author(s):  
Mei-Yu Xuan ◽  
Yi Han ◽  
Xiao-Yong Wang
Keyword(s):  
Compressive Strength ◽  
Electrical Resistivity ◽  
Experimental Studies ◽  
Autogenous Shrinkage ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Hydration Heat ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio

This study examines the hydration–mechanical–autogenous shrinkage–durability–sustainability properties of ternary composites with limestone filler (LF) and ground-granulated blast furnace slag (BFS). Four mixtures were prepared with a water/binder ratio of 0.3 and different replacement ratios varying from 0 to 45%. Multiple experimental studies were performed at various ages. The experimental results are summarized as follows: (1) As the replacement levels increased, compressive strength and autogenous shrinkage (AS) decreased, and this relationship was linear. (2) As the replacement levels increased, cumulative hydration heat decreased. At the age of 3 and 7 days, there was a linear relationship between compressive strength and cumulative hydration heat. (3) Out of all mixtures, the ultrasonic pulse velocity (UPV) and electrical resistivity exhibited a rapid increase in the early stages and tended to slow down in the latter stages. There was a crossover of UPV among various specimens. In the later stages, the electrical resistivity of ternary composite specimens was higher than plain specimens. (4) X-ray diffraction (XRD) results showed that LF and BFS have a synergistic effect. (5) With increasing replacement ratios, the CO2 emissions per unit strength reduced, indicating the sustainability of ternary composites.

Alkali Activation of Granulated Blast Furnace Slag

2010 ◽  
Vol 158 ◽  
pp. 1-11 ◽  
Author(s):  
Zi Qiao Jin ◽  
Xian Jun Lu ◽  
Shu Gang Hu
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Ordinary Portland Cement ◽  
Hydration Product ◽  
Early Age ◽  
Hydration Products ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

In order to stimulate the potential cementitious property of granulated blast furnace slag (GBFS), the ground GBFS sample (Wei Fang Iron and Steel Corporation, China) was activated by lime and gypsum under different dosages. The results showed that lime is an effective activator for the slag, and the optimum dosage of lime is about 10% (w/w) of the slag. At the optimum dosage of lime, the 28 days compressive strength of the lime-slag paste is higher than that of 32.5 ordinary Portland cement (OPC). But, the early age strength (3 and 7 days compressive strength) of the lime-slag paste is lower than that of the OPC. Addition of gypsum can effectively improve the early age strength of the lime-slag paste. At the ratio of gypsum:lime:slag of 8.2:9.2:82.6 (w/w), both the early and long-term compressive strengths of the gypsum-lime-slag paste are higher than that of the OPC. According to XRD, TG-DTA and SEM detections of the hydration products of the lime-slag paste, the gypsum-lime-slag paste and the OPC paste, it reveals that the hydration process of the GBFS-based cementitious material is different from the ordinary Portland cement and the presence of ettringite (AFt) contributes to the early age strength of the pastes. The major hydration product of the OPC paste (<7 days) were measured as ettringite (AFt), but the AFt phase was not detected in the hydration product of the lime-slag paste and the major hydration product of the lime-slag paste was determined as amorphous CSH gel. However, AFt was detected in the hydration products of the gypsum-lime-slag paste in the early stages of hydration, and the formation of AFt is favorable for the early strength improvement of the material.

scholarly journals Evolution of Mechanical Properties with Time of Fly-Ash-Based Geopolymer Mortars under the Effect of Granulated Ground Blast Furnace Slag Addition

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1135 ◽  
Author(s):  
Mateusz Sitarz ◽  
Izabela Hager ◽  
Marta Choińska
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Modulus Of Elasticity ◽  
Blast Furnace Slag ◽  
Energy Savings ◽  
Pulse Velocity ◽  
Partial Replacement ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Geopolymers are considered to alternatives to Portland cement, providing an opportunity to exploit aluminosilicate wastes or co-products with promising performances in the construction sector. This research is aimed at investigating the strength of fly-ash-geopolymers of different ages. The effect of granulated blast furnace slag (GGBFS) as a partial replacement of fly ash (FA) on the tensile (ft) and compressive strength (fc), as well as the modulus of elasticity, is investigated. The main advantage of the developed geopolymer mixes containing GGBFS is their ability to set and harden at room temperature with no need for heating to obtain binding properties, reducing the energy consumption of their production processes. This procedure presents a huge advantage over binders requiring heat curing, constituting a significant energy savings and reduction of CO2 emissions. It is found that the development of strength strongly depends on the ratio of fly-ash to granulated blast furnace slag. With the highest amount of GGBFS, the compressive strength of geopolymers made of fly-ash reached 63 MPa after 28 days of curing at ambient temperature. The evolution of compressive strength with time is correlated with the development of ultrasound pulse velocity methods, which are used to evaluate maturity. The modulus of elasticity changes with strength and the relationship obtained for the geopolymer is presented on the basis of typical models used for cement-based materials. The tensile to compressive strength ratios of the tested geopolymers are identified as higher than for cementitious binders, and the ft(fc) relationship is juxtaposed with dependencies known for cement binders, showing that the square root function gives the best fit to the results.

scholarly journals Estimation of Ground Granulated Blast Furnace Slag and Rice Husk Ash Cementing Efficiency in Low and Medium Grade Self-Compacting Concretes

2019 ◽  
Vol 9 (1) ◽  
pp. 5044-5048
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Rice Husk Ash ◽  
Early Age ◽  
Strength Gain ◽  
Strength Enhancement ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Ternary blended Self Compacting Concrete (SCC) made with rice husk ash (RHA) and GGBFS (ground granulated blast furnace slag) has developed as a substitute to normal concrete. It has advantages such as less cement usage, energy usage, cost and for other ecological and socio-economic benefits. The current work quantifies the 3, 7 and 28-days cementitious efficiency for various percentages of RHA and GGBFS combination in SCC. The usage of GGBFS in M20 and M40 SCC reduces workability but increases compressive and tensile strength when compared with OPC based SCC. The optimum GGBFS is found to be 30% for low and medium strength levels of SCC. For M20 and M40, 30% GGBFS reduces workability slightly but still within desired limits. So after various trial mixes it was found that 27% GGBFS by weight of OPC and 3% RHA by weight of GGBFS quantity can be admixed to OPC SCC to achieve similar strength and workability and also better rate of strength regain in early days of hardening. In M20 and M40 grades of SCC, 3% RHA by weight of GGBFS quantity is replaced. Due to addition of GGBFS to SCC will enhance the later age compressive strength but early age compressive strength decreases while the desired workability is controlled using SP appropriately. This is true for all grades of GGBFS based SCC. In M20 GGBFS based SCC, the strength gain at 3 days is nearly 9% but the compressive strength at 28 days increased by 31%. In M40, GGBFS based SCC, the strength gain at 3 days is nearly 14% but the compressive strength at 28 days increased by 21%. RHA is added as replacement of cement to improve the early age strength of SCC. RHA addition to concrete as cement replacement may help to improve strength marginally but impacts the workability drastically so SP should be used controllably to attain the desired workability. In M20 GGBFS+RHA based SCC, the compressive strength enhancement at 3 days is 21% and the compressive strength at 28 days increased by 46%. In M40, GGBFS+RHA based SCC, the compressive strength enhancement at 3 days is 20% and at 28 days increased by 34%. Similarly tensile strength in all grades of GGBFS and RHA admixed SCC increases by around 15 to 34% in M20 grade and 9 to 36% in M40 grade SCC mix. So it can be concluded that RHA and GGBS combination principally yields early strength which is not possible in SCC mixes primary made with fly ash.

scholarly journals Early-age compressive strength and dynamic modulus of FRC based on ultrasonic pulse velocity

2021 ◽  
Vol 71 (343) ◽  
pp. e257
Author(s):  
D. Castillo ◽  
S. Hedjazi
Keyword(s):  
Compressive Strength ◽  
Dynamic Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Early Age ◽  
Fiber Reinforced ◽  
Different Types

Due to the increasing use of rapid construction methods and the challenges of maintaining construction schedules, a growing demand exists for procedures that can assure quality of work without sacrificing the pace of construction. The quality control of construction materials specifically, the mechanical properties of concrete are among the most important concerns in today’s construction industry. In the present study, the correlation between fiber-reinforced concrete’s compressive strength and dynamic modulus to its ultrasonic pulse velocity is investigated at early ages up to 7 days after mixing. An experimental program involving 189 FRC specimens were designed containing different types of structural fibers, fiber volume fractions, and water-to-cement ratios. Mathematical equations were developed to predict the early-age compressive strength and dynamic modulus of four different types of fiber-reinforced concrete based on ultrasonic pulse velocity. The predicted compressive strength and dynamic modulus from the proposed equations showed good agreement with the measured ones.

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