Effect Of Nano Calcium Carbonate Research Articles

On the effect of nano calcium carbonate on the flexibility and tensile-shear cracking resistance of greener WMA asphalt concretes containing RAP contents

Asphalt mixtures are widely used materials for paving roads, however, they need a significant amount of virgin materials, and their preparation process is environmentally unfriendly. In this regard, using less harmful production processes and using recycled materials can be beneficial. In the current study, the cracking resistance parameters (fracture toughness and fracture energy) of warm mix asphalt (WMA) mixtures, prepared with high contents of reclaimed asphalt pavement (RAP) were investigated, while different contents of nano calcium carbonate (NC) were used as a modifier. The cracking resistance studies were done for the full range of mode I/II fracture conditions. From the results, it is seen, that the addition of RAP increases both fracture toughness and fracture energy, regardless of the mode mixity and NC contents (respectively by an average, of 30 % and 20 %). The NC also made the mixture more resistant to cracking, so the enhancement of fracture energy by up to 30 % and the enhancement of fracture toughness by up to 20 % is observed. The NC optimum content was calculated in the range of 2–4 % (in weight of binder), varied based on the considered variables. As a result of increasing the material’s brittleness by adding RAP and NC, the flexibility index showed a decrease. In separate evaluations, the effect of variables on strength parameters was studied statistically, showing that the fracture toughness in mode II, is about 1.2–1.5 times higher than fracture toughness in mode I. Also, theoretical frameworks were used to predict the trend of fracture data, showing the consistency of experimental results and theoretical predictions.

Synergistic Improvement in Setting and Hardening Performance of OPC-CSA Binary Blended Cement: Combined Effect of Nano Calcium Carbonate and Aluminum Sulfate

The combined effect and corresponding mechanism of nano calcium carbonate (NC) and aluminum sulfate (AS) on the setting and hardening performance of binary blended cement (ordinary Portland cement (OPC) and calcium sulfoaluminate cement (CSA)) were evaluated through multiple experiments, including setting time, calorimetry, compressive strength, X-ray diffraction (XRD), and mercury intrusion porosimetry (MIP). The results showed that, as compared to OPC, OPC-CSA binary blended cement exhibited reduced setting time but decreased early strength, which could be caused by the depressed silicate phase hydration due to the fast supply of aluminate ions during the hydration of aluminate-contained phases contained in CSA. However, through the combined addition of NC and AS, the depressed silicate phase hydration was greatly promoted by NC due to its nucleation effect, and the reduced early strength was significantly improved. Further analysis indicates that the combined addition of NC and AS can promote the formation of C-S-H gel and decrease the porosity of the hardened OPC-CSA binary paste. In this way, one promising repair material with rapid setting and hardening properties was prepared by OPC-CSA binary blended cement with the combined addition of NC and AS.

Effect of Nano-calcium carbonate on the Geotechnical and Microstructural Characteristics of Highly Plastic Paddy Clay

Effect of Nano-calcium carbonate on the Geotechnical and Microstructural Characteristics of Highly Plastic Paddy Clay

The Effect of Nano Calcium Carbonate and/or Recombinant Bone Morphogenetic Protein as a Biological Orthodontic Retainer on the Body Weight of Experimental Rat.

Retention after orthodontic tooth movement (OTM) is essential to prevent relapse. This study examined the effects of a fixed orthodontic device and Nano Calcium Carbonate (CaCO3) nanoparticles with or without recombinant human bone morphogenetic protein (rhBMP) on rat body weight. OTM was administered for 21 days to 80 Wistar Albino rats. First molar mesialization was active then forming two 40-rat groups which were subdivided into four subgroups of 10 rats each. These subgroups received 5 µg/kg rhBMP, 75 µg/kg CaCO3, 80 µg/kg rhBMP-loaded CaCO3 and one control. The relapse rate was examined weekly over the second 21 days when the second group exhibited mechanical retention and the first did not. Group 1 rats were murdered after 21 days (day 42), whereas group 2 rats entered a third 21-day post-retention period and then murdered (day 63). BW and OTM were measured on days 1, 21, 28, 35, 42, and 63. Within each group, the animal body weight was reduced significantly after the intervention and continued over time with a higher average reduction in the 9-week group than the 6-week group. However, there were no significant (P-value ˃0.05) differences in the BW between the groups of the two (6-week and 9-week) sets and the subgroups of the 6-week set across each time point. In contrast, there was a significant (P-value ˂0.05) difference between the BW of the conjugate subgroup and the other three subgroups in the 9-week set, particularly on 63rd day. CaCO3 nanoparticles and/or BMP with orthodontic treatment collectively or individually cause a reduction of body weight in rats.

Effect of nano calcium carbonate (nano CaCO3) on the strength and consolidation properties of clayey sand soil

Nanotechnology is extensively used in engineering to improve systems, characteristics and standards. Various techniques can be used for soil improvement in road embankment and geotechnical engineering. The present study examined the effect of nano calcium carbonate (nano-CaCO3) on clayey sand soil using uniaxial and consolidation tests on specimens containing 10%, 20% and 30% kaolinite and bentonite, and 0.3%, 0.7%, 1.1% and 1.5% nano-CaCO3 at curing times of 7, 14 and 28 days. The results showed that mixtures containing 10% and 20% clay plus 0.7% nano-CaCO3, and specimens with 30% clay and 1.1% nano-CaCO3, exhibited optimal UCS and consolidation properties. XRD patterns indicated an increase in the intensity of the phases (calcium silicate hydrate, kaolin, calcite, etc) after the addition of nano-CaCO3 to the soil. SEM micrographs showed better filling of voids after the addition of nano-CaCO3 to both clay types. The amounts of these products were higher in the bentonite specimens.

Experimental and Numerical Evaluation of the Effect of Nano Calcium Carbonate on Geotechnical Properties of Clayey Sand Soil

Experimental and Numerical Evaluation of the Effect of Nano Calcium Carbonate on Geotechnical Properties of Clayey Sand Soil

Effect of Nano Calcium Carbonate on Some Properties of Reactive Powder Concrete

Concrete is the most commonly used construction material, and its use is expected to rise as the world’s population grows, the economy develops, and aging infrastructure needs to be repaired or replaced. Unfortunately, one of its main constituents, cement, is responsible for approximately 5–10% of global carbon dioxide emissions. As a result, the industry as a whole and the specific material are in desperate need of re-evaluation. In this research, the effects of Nano calcium carbonate (NC) on some properties of reactive powder concrete (RPC) was studied. Nano calcium carbonate (NC) was added at rates(0.75, 1, and 1.5)%. As a partial replacement of cement weight. Reactive powder concrete (RPC) was developed from cement, nano CaCO3, recycled fly ash, silica fume, fine sand, steel fibers, superplasticizer, and water. Compressive strength tests, tensile strength tests, flexural strength were conducted at 7 and 28 days. Water absorption was specified at the age of 28 days. The results showed the addition of NC to the RPC improved the mechanical properties compared with the mixture without NC. also, the incorporating of nano-CaCO3 in RPC will contribute in produced RPC more environmentally friendly by reducing its cement factor, While achieving good engineering properties.

Systemic multi-scale approaches to predict the flowability at various temperature and mechanical properties of cement paste modified with nano-calcium carbonate

In this study, the effect of nano-calcium carbonate (nano-CaCO3) as an additive to the cement paste was evaluated and quantified. Microstructure tests, experimental tests, and modeling were conducted to predict the cement paste's rheological properties namely yield stress (yield point), shear stress limit, viscosity, and stress at the failure of cement at fresh and hardened stages. The cement paste modified with nano-CaCO3 was tested at a water-to-cement ratio of 0.35 with 0.45 and temperatures ranging from 25 to 75 ⁰C. The addition of nano-CaCO3 increased the shear stress limit and the yield stress (τo) by 10.28 to 51.35% and 14.36 to 91.4%, based on the nano-CaCO3 content, w/c, and temperature of the test. TGA tests showed that the 1% nano-CaCO3 additive reduces the weight loss of the cement at 800 ⁰C by 76% due to interacting with the nano-CaCO3 with the cement paste. The nonlinear regressions (NLR) model and Artificial Neural Network (ANN) technical approaches were used for the qualifications of the flow of slurry and stress at the failure of the cement paste modified with nano-CaCO3. Based on the statistical assessments of R and RMSE, the rheological properties such as yield stress, plastic viscosity, shear stress limit and compressive strength of cement paste modified with nano-CaCO3 can be well predicted in terms of w/c, nano-CaCO3 content, temperature, and curing time using two different simulation techniques. Based on the statistical assessments such as coefficient of correlation (R), root mean square error (RMSE), the NLR model is the most effective model to estimate rheological properties and compressive strength of the cement and it is performing better than the ANN model.

Effect of nano calcium carbonate and attapulgite on isothermal crystallization time of polypropylene under static and dynamic conditions

The isothermal crystallization time of polypropylene/nano calcium (PP/CaCO3) and polypropylene/attapulgite (PP/ATP) under static and dynamic conditions were investigated by using differential scanning calorimeter and Rheological experiments. Relatively, in static conditions, the calcium carbonate was easier to accelerate the crystallization process due to its shape. In the shear field the attapulgite is more advantageous to shorten crystallization time indicating that the attapulgite dispersed in the PP matrices confined the PP chains and hindered the movement of the PP chains.

Effects of nano calcium carbonate and siwak toothpaste on demineralized enamel surface roughness

The aim of this study was to analyze the effect of nano calcium carbonate and Siwak toothpaste on demineralized enamel surface roughness. Human tooth specimens immersed in 0.3% citric acid at pH 3.25 were brushed with nano calcium carbonate and Siwak toothpaste for 2, 4, and 6 weeks. Enamel surface roughness was tested using a Surface Roughness Tester with supporting scanning electron microscopy and energy dispersive spectroscopy assessments. It was found the application of nano calcium carbonate and Siwak toothpaste for 2, 4, and 6 weeks decreased the surface roughness of the demineralized enamel (p < 0.05). Brushing teeth with nano calcium carbonate and Siwak toothpaste should decrease the surface roughness of demineralized enamel.

A simple method for preparation of microcellular PLA/calcium carbonate nanocomposite using super critical nitrogen as a blowing agent: Control of microstructure

AbstractA simple method was used to prepare microcellular foams of poly(lactic acid) (PLA) and its nanocomposites to improve its shortcomings such as low impact resistance and high cost. The batch foaming process of pure PLA and PLA filled with Nano calcium carbonate (NCC) was conducted using supercritical nitrogen (N2) as a blowing agent. The effect of NCC on crystallization of PLA is discussed as a remarkable parameter in foaming of semicrystalline polymers. Differential scanning calorimetry (DSC) was used to optimize the process temperature. The effect of foaming conditions (temperature, pressure, and cooling rate) and nanoparticle content on the foam microstructure of PLA and its nanocomposites were investigated using scanning electron microscopy (SEM). Foams were obtained in the range of macro‐ and microscale (different cell sizes) using different foaming conditions. The results revealed that nanoparticles show excellent nucleation performance on PLA foaming. Results of dynamic mechanical thermal analysis (DMTA) also showed significant influences of NCC on foamed and prefoamed samples to different foaming structures.

The effect of nano calcium carbonate on the dynamic behaviour of asphalt concrete mixture

This paper reports on the benefits of nano calcium carbonate (NCC) for asphalt mixtures used on pavements. Asphalt mixtures were prepared with 0, 2 and 4% of NCC, and compacted using the Marshal compactor. To assess the impact of NCC on the dynamic behaviour of hot mix asphalt (HMA), control mixtures (without NCC) and mixtures containing NCC were tested using dynamic creep, indirect tensile fatigue and strength tests. Based on the results, it is shown that the use of NCC to 4% can decrease the rutting potential and increase the fatigue life of HMA. Also, it was found that the addition of NCC decrease the moisture damage potential.

Interfacial Properties of Bamboo Fiber-Reinforced High-Density Polyethylene Composites by Different Methods for Adding Nano Calcium Carbonate.

The focus of this study was to observe the effect of nano calcium carbonate (CaCO3) modification methods on bamboo fiber (BF) used in BF-reinforced high-density polyethylene (HDPE) composites manufactured by extrusion molding. Two methods were used to introduce the nano CaCO3 into the BF for modification; the first was blending modification (BM) and the second was impregnation modification (IM). In order to determine the effects of the modification methods, the water absorption, surface free energy and interfacial properties of the unmodified composites were compared to those of the composites made from the two modification methods. The results revealed that the percentage increase in the weight of the composite treated by nano CaCO3 decreased and that of the IMBF/HDPE composite was the lowest over the seven months of time. The results obtained by the acid-base model according to the Lewis and Owens-Wendt- Rabel-Kaelble (OWRK) equations indicated that the surface energy of the composites was between 40 and 50 mJ/m2. When compared to the control sample, the maximum storage modulus (E′max) of the BMBF/HDPE and IMBF/HDPE composites increased 1.43- and 1.53-fold, respectively. The values of the phase-to-phase interaction parameter B and the k value of the modified composites were higher than those of the unmodified composites, while the apparent activation energy Ea and interface parameter A were lower in the modified composites. It can be concluded that nano CaCO3 had an effect on the interfacial properties of BF-reinforced HDPE composites, and the interface bonding between IMBF and HDPE was greatest among the composites.

Effect of Nano-Calcium Carbonate on the Mechanical Properties of Polypropylene

The task of the polymer physics experiment course is using a certain percentage of nanocalcium carbonate (CaCO3) to composite polypropylene (PP) and using a twin-screw injection molding machine to inject the compound above into a standard sample. After that some mechanical properties test were made to get some nanocalcium carbonate data which may affect the mechanical properties of polypropylene.

Studies of poly(lactic acid) based calcium carbonate nanocomposites

The effect of nano-calcium carbonate on chain linked poly(lactic acid) was investigated. In order to improve inorganic nanofillers/polymer compatibility CaCO3 nanoparticle surface was treated by stearic acid. The nanocomposites were prepared by means of solution blending and further studied by using dynamic mechanical analysis, fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. Morphological analysis performed on nanocomposites fractured surfaces has revealed that the CaCO3 modification induces homogeneous and fine dispersion of nanoparticles into polymer as well as strong interfacial adhesion between the two phases. An increase in the Tg and storage modulus of the resulting nanocomposites was observed with the increase of calcium carbonate ratio. Thermogravimetric results showed a lower degradation temperature with the increase of calciium carbonate ration in the polymer matrix.

Study on mechanical properties of nano-calcium carbonate/thermoplastic composites

This is a study on evaluating the effect of nano-calcium carbonate (CaCO3) particles on the mechanical properties of thermoplastic casts, which were performed by mechanical tests, such as scanning electron microscopy and energy dispersive spectroscopy. Composites loaded with a mass rate of 1–2 wt% of nano-CaCO3 particles in polyethersulphone (PES) showed the most excellent mechanical function. The increase in the rate of compressive strength, the maximum compressive modulus and the flexural modulus increases is 47%, 51% and 32% in contrast to neat thermoplastic resin, respectively. The improvement in mechanical properties is attributed to the nanocomposites based on the modified nano-CaCO3 fillers that perform higher modulus and lower Poisson’s ratio than neat PES resin.

Effect of nano-calcium carbonate on early-age properties of ultra-high-performance concrete

In this study, the effects of nano-calcium carbonate (CaCO3) addition on the early-age properties of ultra-high-performance concrete cured at simulated cold and normal field conditions were investigated. The nano-CaCO3was added at rates of 0, 2·5, 5, 10 and 15% as a partial volume replacement for cement. Similar mixtures incorporating chloride- and non-chloride-based accelerating admixtures were also tested for comparison. Results indicate the high potential of nano-CaCO3to accelerate the setting and hardening process of ultra-high-performance concrete through providing nucleation sites, increasing contact points and increasing the effective water-to-cement ratio. Although nano-CaCO3exhibited a comparable or slightly lower accelerating effect to that of the chloride- and non-chloride-based accelerating admixtures, it brings a number of benefits to concrete production. These include the development of low-maintenance structures through eliminating the risk of steel corrosion induced by chloride-based accelerating admixtures, as well as a more environmentally friendly concrete through reducing the cement factor of ultra-high-performance concrete.

Effect of Nano Calcium Carbonate and Montmorillonite on Properties of Styrene–Butadiene–Styrene Copolymer Modified Asphalt

Composite modified asphalts with nano calcium carbonate (nano CaCO3)/ SBS and nano montmorillonite (nano MMT)/SBS were prepared respectively by melt blending. Rolling thin film oven test (RTFOT) was carried out to study the aging properties. The results demonstrate that CaCO3/SBS and MMT/SBS homogeneously disperse in the base asphalt, which lead to an improvement in terms of toughness, strength, and thermal stability. Effects of the nano CaCO3 and nano MMT on the properties of SBS modified asphalt appear as a decreasing penetration, an increasing softening point, and a decreasing ductility. The anti-aging property of the nano MMT/SBS modified asphalt was better than that of the CaCO3/SBS modified asphalt and SBS modified asphalt.

Effect of nanocalcium carbonate on the impact strength and accelerated weatherability of rigid poly(vinyl chloride)/acrylic impact modifier

AbstractPoly(vinyl chloride) (PVC) composites filled with nano‐ and micro‐CaCO3 particles were prepared via a melt blending method. Transmission electron microscopy images revealed better dispersion of nano‐CaCO3 than micro‐CaCO3 in the PVC matrix. With more than 5 phr (parts per 100 parts of resin) of nano‐CaCO3 content, both impact strength and heat stability were improved. Accelerated weathering tests were performed to investigate UV stability. The impact strength and white index obtained upon weathering exposure of PVC/(80 μm CaCO3) nanocomposites showed a significant improvement upon incorporating nano‐CaCO3. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers