On the Relation of Setting and Early-Age Strength

mortar cubes and concrete cylinders) and cumulative heat release normalized per unit volume of (mixing) water for a wide variety of cement-based mixtures at ages of 1 d and beyond. This paper utilizes concurrent ultrasonic reflection and calorimetry measurements to further explore this relationship from the time of specimen casting to 3 d.

Learn More

Self-Shrinkage Behaviors of Waste Paper Fiber Reinforced

When cement paste was cured for 7 days, it was found that the diffraction intensity which was in Ca(OH) 2 peak at about 18° of cement paste containing 0.2% WPFs was significantly higher than control sample and cement paste containing 0.3% WPFs; it showed that more hydration products were formed in cement paste containing 0.2% WPFs.

Learn More

Materials | Free Full-Text | Properties of Cracking

The research presented in this paper presents a quantitative analysis of cracking patterns on the surface of cement paste, which has been modified by the addition of the multi-wall carbon nanotubes (MWCNTs). The cracking patterns analyzed were created as a result of increased temperature load. MWCNTs were used as an aqueous dispersion in the presence of a surfactant, sodium dodecyl sulfate (SDS).

Learn More

Influence of internal sulfate attack on cement paste

Since the cement pastes have no aggregate to apply the amounts, a mix proportion of base concrete was used to then determine the amounts regarding the mass of cement. The concrete mix proportion adopted was: 1.0 kg of cement, 2.7 kg of fine aggregate, 2.7 kg of coarse aggregate and 0.6 kg of water.

Learn More

Experimental Studies on The Homogeneity and Compressive

To do so, the ultrasonic pulse velocity (UPV) measurements through a concrete sample were performed to interpret the homogeneity of RAC, and to predict the RAC compressive strength. The selected concrete waste (concrete ruins of 30 ≤ fc' ≤ 35 MPa) was used as natural aggregate substitution material for the new concrete. The same mix

Learn More

Using Contactless Ultrasonic Method

the contactless ultrasonic method is applicable to cement paste, mortar, and concrete. Hong et al. [17] indicated that the definition of the time-zero point by the contactless ultrasonic method is more accurate compared to ASTM C 403 under accelerated curing. In this study, we present further improvements to the contactless ultrasonic method

Learn More

Temperature and humidity influence on the strain sensing

Temperature and humidity influence on the strain sensing performance of hybrid carbon nanotubes and graphite cement composites Beatriz del Morala, F. Javier Baezaa, Rosa Navarroa, Oscar Galaoa, Emilio Zornozaa, Jose Verab, Catalina Farcasa, Pedro Garcésa,⇑ a Department of Civil Engineering, University of Alicante, Carretera San Vicente s/n, 03690, San Vicente del Raspeig, Spain

Learn More

concrete mixing equipment Argentina

Top 11 Best Cement Mixers Best Concrete Mixers ( ) Buying a Cement Mixer vs. Ordering Concrete. Some people have minds like cement – thoroughly mixed-up and permanently set. But if you have an upcoming project that includes a fair amount of concrete work and need the best cement mixer or best concrete mixer you need to know your options

Learn More

Influence of Seawater in Strengths of Concrete Mix Design

In this paper, the effect of seawater on concrete mix was studied. Seawater was fetched from the Red Sea near Port Sudan. Forty eight concrete cubes were prepared using constant water/cement ratio. The first two groups were both mixed with fresh water then cured in fresh water and seawater, respectively. The third and fourth groups were both mixed with seawater but cured in seawater and fresh

Learn More

Effect of sulphates in cement (containing 5% pozzolana

The above study is for 1:2:4 concrete mix. In this work the effect of sulphates m cement, with 5% pozzolana, and in sand on the correlation between compressive strength and U.P.V. concrete of different mixes such as 1:1.5:3, 1:2:4, and 1:3:6 may be studied in order to

Learn More

Observation of cement paste microstructure evolution

During early hydration in fresh concrete, the cement paste hardens and bonds the aggregates together to make a solid concrete mass. During this process, along with chemical reactions, physical changes in the cement paste at the microlevel and the nanolevel also play major roles in the development of the properties of the concrete.

Learn More

ASTM International - Cement, Concrete and Aggregates

A Statistical Analysis of Hot and Warm Accelerated Concrete Curing Methods. Ultrasonic Testing to Determine Water-Cement Ratio for Freshly Mixed Concrete. Rheology of Cement Paste and Concrete. A Systematic Method to Determine Optimal Specimen Geometry for Measuring Concrete Fracture Properties by the Peak-Load Method

Learn More

Ultrasonic Techniques for Air Void Size Distribution and

2.1.1. Attenuation Generated by Cement Paste and Aggregates The attenuation generated by the cement paste matrix a,f can be directly measured with the ultrasonic scattering measurement on the separately prepared cement paste with the same water/cement ratio. The aggregate size distribution G(ai1) can be determined with the designed aggregate

Learn More

PDF Table of Contents How to write a laboratory report?

Concrete Mix Design Velocity of Ultrasonic Pulses in Concrete The standard consistency of a cement paste is defined as the water to cement ratio which will permit a Vicat rod having 10 mm diameter and 50 mm length to settles to a point 10±1 mm below the original surface of the mould

Learn More

Optimization of Concrete Wall Formwork Using Ultrasonic

Mix No. Mix Type Cement type Cement Wate r Aggregates Max. particle size 1 cement paste CEM I 32.5 R 1 0.257 - - 2 mortar CEM I 32.5 R 1 0.5 2.23 2 mm 3 concrete CEM I 32.5 R 1 0.5 4.25 8 mm 4 semi hydrate paste semi hydrate 1 0.167 - - 5 clinker paste cement clinker 1 0.253 - - 4.2. Ultrasonic

Learn More

Effect of Admixtures on Dynamic Elastic Modulus of Cement

The elastic modulus of cement paste is the key parameter for characterizing the mechanical response of concrete. In modern concrete technology, the admixtures are often used to enhance the performance of concrete. This paper introduces a nondestructive testing method to evaluate the dynamic elastic modulus of cement paste. Moreover, the effect of water-cement ratio and conventional admixtures

Learn More

PDF Assessment of physical and mechanical properties of

Table 1. Mix Proportions. Concrete Percentage of sand replaced by sawdust Mix Proportion, in volume Cement Sand Sawdust Coarse Aggregate T1 0 1 2 0 1.2 T2 25 1 1.5 0.5 1.2 T3 50 1 1 1 1.2 T4 75 1 0.5 1.5 1.2 T5 100 1 0 2 1.2 2.3 Ultrasonic Pulse Velocity (UPV) Measurements

Learn More

The extension of thixotropy of cement paste under

Cement paste is a particle stream formed by mixing water and cement particles and concrete consists of cement paste and aggregates. Research on cement paste and fresh concrete is closely linked. The change of rheological properties of fresh concrete under vibration mainly comes from cement paste.

Learn More

Cement Reaction and Resultant Physical Properties of

Cement reaction and resultant physical properties of cement paste Ippei Maruyama, Go Igarashi Journal of Advanced Concrete Technology,volume ( ), pp.12 200-213 Characterization and Modeling of Pores and Surfaces in Cement Paste: Correlations to Processing and

Learn More

The Effect of Complex Modification on the Impedance of

The research results presented in this article were obtained by joint scientific research on creatingcement materials with reduced impedance. It is known that functional additives

Learn More

Assessment of Concrete Residual Strength at High

cement paste associated to dehydration of the cement paste due to decomposition of the calcium silicate hydrate (C-S-H) [3]. One of the successful techniques for detection of chemical and physical changes and damage in concrete is the use of nondestructive testing methods. On this study, the

Learn More

Frequently Asked Questions

The American Concrete Institute. Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design

Learn More

Non-Destructive Evaluation of Concrete using Ultrasonic

a paste content of 18% and the constituents of the specime ns varied in different water-cement ratios (w/c). The UPV measurement and compressive strength tests were carri ed out at the concrete

Learn More

Ultrasonic characterization of the curing process of PCC

Abstract The effects of the type of fly ash, mix proportion, and curing process on the pozzolanic reaction of fly ash-cement paste were investigated by ultrasonic techniques. Specifically, the speed of sound (SOS) and broadband ultrasonic attenuation (BUA) were used to investigate hydration activities of the fly ash-cement composite. SOS provided direct evidence of the delay in the

Learn More

PDF Ultrasonic monitoring of setting of green concrete

Green concrete, ultrasonic, setting, fly ash, slag, early age - determining the setting of cement paste by the needle Vicat; 3 Mixing Technique In the reference mix with OPC, the quantity of cement and net water was fixed to 303 kg/m3 and 182 kg/m3 respectively. The green concretes had to satisfy the following

Learn More

PDF An Experimental Study on the Use of Magnetized Water in

Mix proportion: The mix is designed by using the data from the material tests. The mix proportion for M20 concrete designed as per provisions in IS 10262-2009.The mix proportion is given in table 4. Table 4: Mix proportion of M20 concrete Water Cement Fine aggregate Coarse aggregate 197 L 394 kg 726.544 kg 1314.88 kg 0.5 1 1.84 3.33

Learn More

Leave a Reply

Your email address will not be published. Required fields are marked *