the cementmortar that determines the specific properties of this concrete [ 1 ].
The composition of the self-compacting cementmortar (SCM) is characterized with (i) a large diversity of water-reducing admixtures, (ii) a high content of
Authors:V. Stoyanov, B. Kostova, V. Petkova, and Y. Pelovski
The decorative cementmortars and concretes are an artificial imitation of the natural stones. The main advantage of these artificial stones is their better workability, but the durability and stability are their
The present study is based on the influence of the addition of a pozzolanic material as a result of the activation of an industrial
waste coming from the Spanish paper industry on the heating as well as hydration heat of the cement mortars made with 10 or
20% of active addition.
Once the sludge has been calcined at different temperatures (700–800°C) and stays in furnace (2 and 5 h), the calcined products
showed high pozzolanic activity. The maximum activity corresponded to the paper sludge calcined at 700°C for 2 h (S1). Besides,
it can be proved that there was an increase both of the heating and also of the hydration heat in the first 23–25 h for both
additions (10 and 20% of S1) regarding the reference cement mortar. This behaviour would be related to the influence of different
effects: filler and pozzolanic during the first hours of reaction, and by the dilution effect for longer hydration times,
mainly when 20% of S1 was added.
Authors:M. García de Lomas, M. Sánchez de Rojas, and M. Frías
This work presents the relation between the pozzolanic activity, the hydration heat and the compressive strength developed
by blended mortars containing 10 and 35% of a spent fluid catalytic cracking catalyst (FCC).
The results show that, in comparison with 100% Portland cement mortar, a mortar with 10% FCC increases the hydration heat
all over the period of testing. This hydration heat increasing is due to the pozzolanic effect, therefore the resulting compressive
strength is higher than the reference mortar. Whereas, in a mortar with 35% of FCC, the hydration heat is higher than 100%
PC mortar, until 10 h of testing. After this age, the substitution degree predominates over the pozzolanic activity, showing
in this case, lower hydration heat and developing lower compressive strength than 100% PC mortar.
The chemical corrosion and the mechanical strength were studied in cement mortars containing an additive of FBCC under conditions
of long-term action of sodium sulphate solution or saturated brine. The observations have shown that saturated brine is a
more aggressive agent, since it leaches Ca(OH)2 and contributes to the decomposition of the C-S-H phase thus worsening the compressive strength as compared with that of
mortars kept in water. The addition of 20% FBCC inhibits the leaching process and counteracts the decrease of compressive
strength in mortars kept in brine. On the other hand, sodium sulphate solution changes favourably the mortar microstructure,
increases of the content of small pores and improves both the compressive and the flexural strengths, as compared with those
of a mortar kept in water.
Authors:M. Ismail, M. Ali, A. El-Milligy, and M. Afifi
The effect of impregnation time on the physico-chemical and mechanical properties of polyester-cement mortar composite has
been investigated. The samples were soaked in unsaturated polyester resin containing 40% styrene monomer at impregnation times
ranging from 1–15 hours and then exposed to 50 kGy of γ-irradiation. The effects on polymer loading, compressive strength,
apparent porosity, and water absorption in addition to IR spectra and TGA of the samples were studied. It was found that,
the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and there is no significant
improvement of the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and
there is no significant improvement of the polymer loading and strength. Whereas, the apparent porosity and water absorption
behave in an opposite direction. These are attributed to the presence of polymer in the pores of the samples. IR spectra showed
that, new bands appeared as result of the reaction between polyester and set cement. TGA showed that, the polyester cement
composite has higher thermal stability as a compared to irradiated polyester.
Authors:Eethar Thanon Dawood and Marwa Saadi Mhmood
was partially replaced by SSP, GP, and WA by weight in the quaternary levels. 3 The method 3.1 Flow test on mortar The standard test method for flow of hydraulic cementmortar, determines how much a mortar sample flows when it is unconfined and
The influence of spent catalyst from catalytic cracking in fluidized bed on the hydration process of cement and the properties
of cement mortars were studied. The spent catalyst was used as an additive to cement in the mortars (10 and 20% of cement).
The samples of mortars kept in water for28 days, then they were placed in sulfate and chloride media for 2 months (the control
samples were kept in water for 3 months). After this time they were subjected to bending strength and compressive strength
determinations. Thermogravimetric and infrared absorption studies were performed and capillary elevation, capability of binding
heavy metals, and changes in mass and apparent density were determined too. The studies disclosed the pozzolana nature of
spent catalyst and its influence on cement mortars being in contact with corrosive media.
Authors:L’. Krajči, S. Moujmdar, M. Kuliffayová, and I. Janotka
Two types of raw materials, original kaolin sand OKS I and OKS II were used for experiment. They were transformed (1 h at
650 °C with 10 °C/min temperature increase) to burnt kaolin sand (BKS I and BKS II) with pozzolanic properties. Contents of
decisive mineral—metakaolinite—in BKSs are as follows: BKS I (fraction below 0.06 mm) 20%; BKS II (fraction below 0.06 mm)
36% and BKS II (fraction below 0.1 mm) 31% by mass. Mortars with blends of Portland cement (PC) and BKS were prepared announced
as: MK I (0.06) with 5 and 10% cement substitution by metakaolinite; MK II (0.06) with 5 and 10% cement substitution by metakaolinite
and MK II (0.1) with 5, 10, 15 and 20% cement substitution by metakaolinite. The reference mortar with 100% of PC was made
for comparison. All mortars were adjusted on the constant workability 180 ± 5 mm flow. Besides significant increase in compressive
strengths—the refinement of pore structure in mortars with BKS connected with decreases in permeability and Ca(OH)2 content were revealed. The above facts confirm pozzolanic reaction of BKS in contact with hydrated PC and indicate perceptiveness
of BKS for the use in cement-based systems as a pozzolanic addition.