Newly developed cement–ground granite scraps composite for solidification/stabilization of radioactive wastes: characterization and evaluation of the mechanical durability

The core objective of the present study is to develop an added value cement–granite composite (CGC) based on granite (G) scraps and Ordinary Portland Cement (OPC). The granite scraps were collected, washed, ground, sieved, and the finest powder was used as an inorganic admixture for developing the CGC. Plain water was added to the granite–cement powder and thoroughly mixed. The obtained pastes were casted for 28 days prior to their physical, structural, thermal characterizations and their mechanical evaluation. Factors assumed, mostly, to affect the final properties of the CGC blocks, e.g. granite/cement and water: cement ratios were studied. The reached monolith cement–granite composite has many advantages, e.g. lower density, very low water absorption percentage, acceptable compressive strength values and significant radiation and thermal stability. Based on the experimental data reached it could be stated that: for its economical advantages, where the one of its basic components is a waste. In addition to the acceptable mechanical traits of the developed composite, it can be candidate properly as an inert matrix for some radioactive wastes containment, for application in many field including: construction sector (interior and exterior of household walls, floor tiles, etc.), and for many others. The environmental reward due to management the accumulated problematic solid granite scraps is, certainly, a gain.


Introduction
The serious shortage of natural resources has motivated the current research scenarios to use different kind of complementary fine aggregates and supplementary cementitious materials to develop alternative item for the traditional ones [1].
The utilization of cementitious materials for radioactive waste incorporation included two main outlines: as an inert matrix for direct solidification/stabilization of radwaste with or without treatment [2]; and as an engineered barrier aiming at secondary protection in the form of concrete or grout [2][3][4].
Therefore, instead of using special cement, for a nominated application, it can enhance some of the ordinary cement characteristics through incorporating a proper additive or admixture to perform that application.
Granite or marble residues can be applied either to develop a new products or as an admixture and, hence, the natural sources are utilized more efficiently and the environment is conserved from dumpsites of these wastes [5][6][7]. It is reported that the stone industry produced an annual output of 68 million tons of finished products [8,9].
What is more the production of cement-granite composite based on fine granite powder, is more environmental friendly and sustainable, owing to reduced energy consumption for raw materials production and consequently the greenhouse gases emission, in addition to get rid of huge amount of accumulated granite scraps waste.
Marble and granite wastes are ones of the major worldwide environmental problems and they mainly comprise marble scraps and very fine powders. These waste materials are applied to enhance some properties of fresh and hardened end-product characteristics of mortar and concrete [6].
As the result of defects and cracks in the mined granite rock mass, only about 20-30% and rarely more than 50% of the granite quarried can be marked as commercial blocks. Quarrying waste includes poor quality stone, unshaped lumps, and finger fragments which disposed of in dump found nearby that causing sever impacts to environmental and health risks to man. In addition, about 60% of the volume of original blocks is wasted due to sawing, cutting and finishing operations. Those scraps are disposed of in landfills after the tailing ponds and accounted, also, for ecosystem damages [10]. Environmental crisis can happen as a result of uncontrolled release of these wastes in local open habitats. On the other hand, utilization of the granite wastes, like any other waste, is not only to avoid an environmental pollution due to their accumulation, but also of the contribution to the economy.
The present work presented a method for a developed cement-granite composite based on ground granite waste scraps and Ordinary Portland Cement by replacing the cement with higher contents of stone quarry powder (up to 50% relative to the mass of cement). For evaluating the performance of the generated cement-granite composite in different candidate applications specially radwaste solidification, various parameters that can affect the physical, thermal and mechanical properties of CGC were studied systematically.

Granite powder
The granite powder used in this study is ground granite scraps waste which is very easily available and nearly free of cost. It assumed to add good mechanical properties to the developed cement granite composite.
Scraps wastes as by-products from granite cutting were collected from local workshops contain mud and debris. Those scraps were cleaned with water then air dried under sun. The dried scraps were ground in a high speed mortar mill for 10 min for every 50-60 gm of sample, then sieved to separate the different particle sizes and the lowest particle size powder (mesh size ≈ 100-150 micron) was used in the present work, assuming that the finest particle size ensures better mechanical properties. The ground sieved granite powder (G) was dried again in an oven at 60 °C for 24 h then subjected to XR-Fluorescent (XR-F) analysis. Table 1 and Fig. 1 represent the XR-F analysis of the granite powder and indicated that G is composed mainly of SiO 2 (69.98 mass %), Al 2 O 3 (14.27 mass %), K 2 O (5.47 mass %), Na 2 O (4.1 mass %) and Fe 2 O 3 (3.07 mass %), in addition to some residual of alkaline and alkaline earth oxides. The Loss On Ignition value (LOI) for the G prepared is 0.39.

3
The low percentage of (LOI) indicates that the firing reactions present an insignificant weight loss. Moreover, the presence of Fe 2 O 3 component was characteristic of the chemical composition of natural granite, contributing to the faint reddish appearance [7,11]. Based on X-ray diffraction (XR-D), Fig. 2, the crystal architecture of granite waste powder comprises mainly of: Quartz (SiO 2 ); Anortite (combination of: Na 2 O, CaO, Al 2 O 3 and SiO 2 ); Microcline (KO.Al 2 O 3 .3SiO 2 ), in addition to Ablite, (due to the presence of CaO), and Biotite, (Fe 2 O 3 its main constituent). The great stiffness of granite stone attributed to its high quartz phase content. Moreover, the great proportions of silica and alumina in G are coexisting with the abundant aluminosilicate phases in the XR-D pattern [7,12].
The thermogravimertic analysis (TGA) was performed for the powder G under nitrogen atmosphere with heating rate 10 °C/minute and Al 2 O 3 as reference material using SDT Q 600 V instrument. The data reached are depicted in Table 2.
It is clear from Table 2 that granite powder showed ≈ 3.74% mass loss up to 1000 °C. Granite stone consisted mainly of a group of crystalline inorganic constituents. The TG  thermogram for G, The onset of the first mass loss started at room temperature ended near 430 °C with mass lost ≈ 0.811%. This loss can be referred to the water adhered to the surface of the granite powder. The second step is started at 430 °C and the endset at 610 °C with mass loss ≈ 1.8% and can be due to the dehydration of intra and inter layer crystalline water. The last step happened past 610 °C with mass loss 1.1% and can be attributed to the destruction and oxidation of some granite's inorganic constituents. It should be notified that the total mass loss percentage, up to 1000 °C, was only 3.74% which indicate the high thermal stability of the granite filler. The dehydration and dehydroxylation of organosilica took place between 250 and 625 °C, [12], while the boehmite particles were decomposed into γ-Al 2 O 3 particles at 300-500 °C [13].

Ordinary portland cement
Ordinary Portland Cement (CEMI, N 42.5) is local cement manufactured according to the Egyptian standards ES 4759-1/2013. The chemical composition of Portland cement used is summarized in Table 3. Table 4 describes the main oxide compositions, their chemical formulas, and abbreviations, in addition to listing the average of each in commercially available Ordinary Portland Cement (mass %) [14].

Water
In this work plain water free from organic ingredients and impurities was used for mixing of cement and granite. The concentration of some ions of interest in the water used is represented in Table 5.

Plain cement mix (C)
At ambient temperature, OPC powder was mixed with plain water at 0.35 water/cement (w/c, mass to mass) ratio for preparing samples without any additives and used as control specimens for comparison.

Mixture formulations
The composite mixture formulations were carried out in fulfilment with the rule and practice followed in our laboratory. Granite waste powder was dried before preparing composite mix. The percentage of G powder substituting cement was diverse in steps of 1-(10%, 15%, 20%, 30%, 40% and 50%). All those formulations were prepared for water / (C + G) ratio 0.35 (mass/mass). For the sake of comparison, specimens having three water/cement ratios, namely 0.30, 0.35 and 0.4 and 20% granite powder calculated relative to the used cement were formulated.

Cement-granite composites (CGC) preparation
CGC was acquired through mixing granite waste powder (as an admixture) with the cement clinker before mixing with water. Plain water was added gradually, mixed thoroughly to produce homogenous paste. The acquired composite mixture paste was then casted in the polyethylene moulds with specific dimensions required for testing and characterization. A thin layer of Vaseline was applied to the moulds before pouring the composite mixture. The casting process was performed under ambient room temperature and atmospheric pressure. The moulds were firmly covered to avoid the evaporation of water of hydration during hardening (strengthening, solidification) and curing time. The different compositions of the CGC samples were left for curing and hardening, under their water moisture, for 28 days casting to assure complete curing and the masses of the prepared blocks were measured periodically. The hard specimens were demoulded at the end of curing period (28 days) and subjected to different characterizations, measurements and evaluations. Mass losses during hardening and curing were calculated for the various formulations according to the coming relation: where ML% is the mass loss of the specimen at the of curing period in percent, Mt is the mass of the specimen at the end of curing period (t), and Mo is the mass at the onset time of casting the composite. Compression measurements were determined according to ASTM D 695 on three to five cylindrical blocks with dimensions 4.32 cm diameter, 3.54 cm height and with 1465 mm 2 surface area using Ma-Test Measuring Machine E 159 SP, Italy. The compression load was applied at a rate of 3 kN/s by using a compression machine with a capacity of 1000 kN.

Thermal analysis
Thermo Gravimetric Analysis (TGA) and Thermal Analysis Differential (DTA) were performed for neat cement and cement-granite composite samples at the age 28 days. Small pieces of specimens were collected from the nominated samples crushed post compressive strength testing. Those pieces were then grounded for fine powder. TGA and DTA were carried out using TA-60 WS thermal analyser and Shimadzu DTG-60H Differential Thermal Gravimetric Analyser.

Scanning electron microscopy (SEM)
Surface morphology of the prepared a plain cement block and for a final waste form has w/c ratio 0.35 and immobilizing 20% and 50% waste granite powder were viewed by a high resolution scanning electron microscope (SEM Quanta FEG 250 with field emission gun, FEI Company, Netherlands). Before examination, the solid samples were fixed on stubs and sputter coated with gold in a vacuum evaporator (Cressington Sputter Coater 108, UK). Imaging was performed within three magnifications 25X, 2000X, 15,000 X and 30,000X.

Results and discussion
In the present work a developed formulation of cement-granite composite was obtained from mixing ground granite scraps waste powder, as an inorganic admixture, with cement paste, as a matrix. In addition to the considerable environmental rewards, recycling of granite scraps, as an industry, is directing its driving force from the elevated cost and increase applications of cement raw materials. Also, besides the ecology profits due to use and incorporation of an inorganic waste admixture, it results in an outcome of non-biodegradable long-span engineering products.
The main accountable factors for wide applications of cementitious products are mould ability, proper setting and hardening, acceptable mechanical durability, radiation stability and acquiring the needed properties with admixture to be utilized in definite applications. Table 6 depicts the mass losses during the curing and hardening of the CGC as function of increasing percentages of the granite powder admixture at 0.35 water/cement and granite mass ratio. It is clear that, there were non-significant mass losses for the various composite formulations under consideration. It is worth to state that the highest mass loss record at the end of the curing period (i.e. 28 days) was not more than ≈ 0.50%. Moreover, there were no signs of spilling or cracking for all the solid CGC blocks prepared at the end of hardening and setting duration. This data can be taken as an indication for structural stability of the proposed composite and consequently can candidate the cement-granite composite under study as a potential solidifying/stabilizing matrix for some categories of radioactive waste.

Compressive strength characterization
Compressive strength evaluation was performed as an indication for mechanical integrity [15], and it is a crucial issue for safe handling and transport of radioactive waste forms prior to disposal [16] when applied the developed composite as a matrix for immobilization of radioactive wastes. It is clear from Fig. 3 that increasing the concentrations of the G powder at the expanse of cement keeping the water ratios constant, i.e. 0.35, relative to the mass of cement and granite powder accompanied, first, with a significant increase in the compressive strength value to reach 33.5 MPa at 5% G admixture. Moreover, increasing the granite content resulted in reduction in the compressive strength values to 25.3 MPa at 15% of the granite added which is still greater than the value of plain cement compression. The escalation in the compressive strength values at the ratio of 15% granite content can be attributed to the privileged strength of natural granite stone and the apparent stronger bond with cement paste [17]. The explanation for no spilling or cracking in cement specimens can be due to the reduction in pores numbers of the composite blocks as a result of accessing of the fine particles of granite powder in-between the cement grains, and consequently the increments in compression values [18].
Summing-up, granite powders as admixtures may partially contribute chemically in cement hydration reactions. Moreover, these admixtures can disclose physical role by functioning as nucleation spots for the cement hydration products.
Continuous escalating the G percentages on the expanse of the OPC in the CGC formulation led to significant decreases in the compression of the hard blocks. Similar behaviour was reported by Valls et al. [19], and Lakhani et al. [20], used Table 6 The mass losses at 28 days curing time due to setting and hardening of the CGC containing increasing percentages of granite at 0.35 w/ (C + G) ratio marble dust as admixture. According to Türker et al. [21], the reported reductions in the compression by raising the granite contents behind 15% in the composite can be attributed to the dilution in cement fractions of C 2 S and C 3 S, oxides which are considered the crucial constituents determining the end products strength. In addition, keeping the water added constant while increasing the granite admixture can affect the workability of composite. Additional explanation for the lower compressive strength, compared to the control formulation, as escalating the granite admixture contents more than 15%, can be attributed to more capillaries produced in the final product due to the added granite while keeping the water for mixing constant. Similar conclusion was reached by Topcu et al. [22]. Moreover, part of the water was utilized for wetting the additional percentages of granite, i.e. > 15%, the water acquired by the granite powder is withdrawn from the mixing water, and at this low water content; a reduction in hydration reactions of cement oxides can happened. It is worth to clarify that raising the G powder content in the CGC formulation causes reduction in flowability and consequently the workability of the composite paste.
Regression analyses with R 2 value was 0.836, i.e. close to unity, which representing good correlations between the compressive strength values for the cement-granite composite under study and the G contents, moreover, expressing the trend significantly.
The developed composite under consideration at 4% granite content possessed the highest compressive strength value that ≈ 40% of 28 days compressive strength of the control one, i.e. has zero G powder. Underlying the compressive strength specifications, the formulated composite, under study, can be safely acceptable, also, as construction item, where it can full fill the Egyptian specifications for structural requirements (7 MPa) [17].
Consequently, and based on the compression measurements, the composite formulated from OPC at 0.35 (water/cement and granite) mass ratio and containing up to 50% granite as an inorganic admixture can be candidate as an inert matrix for solidification/stabilization of some categories of low and intermediate level radioactive wastes.
Water/cement ratio (w/c) is one of the main crucial elements affecting mechanical integrity of final solid cement-granite composite. Moreover, it is the principal factor affecting the hydration process of the cement ingredients. According to Hu et al. [24], the w/c is controlling the amount of water required for cement hydration reactions. The w/c ratio can, also, mastering the spacing between the hydrated cement particles. Table 7 demonstrated that the all composites formulated at w/c relative to the cement only and the granite powders were added as excess admixtures showed lower compression values compared to the formulations where granite added on the expanse of cement and water used calculated relative to the mass of both cement and granite.
Although at lowest water added (30%) highest compressive strength values were obtained, yet the mixture was stiff and demonstrating very down workability and hard to cast the mix due to the added granite, especially, when its amount calculated Table 7 The impact of the amount of water added on the compressive strength of the final granite-cement composite NB All the ratios were calculated as mass-to-mass *Average for three blocks **20% dry granite powder added relative to the cement and the water calculated relative to the cement only ***20% dry granite powder calculated on the expanse of dry cement and the water added relative to the sum of cement and granite mixture over relative to cement. On the other hand at the ratio 40%, much water resulted in fluid mix and bleeding could occur led to permeable product with low compressive strength [25]. Therefore, the water at the ratio 35% was chosen to formulated the cement granite composites though out the whole study. In general, the presence of sand replacing a small portion of coarse aggregate (up to about 10%) seems to improve freeze-thaw durability of pervious concrete.
Adding granite to the cement without conform water-to-cement ratio, will most likely be detrimental and resulted in lower W/C ratio, leading to hard workability and reduced densities. Therefore, replacement of the portion of the granite admixture is preferable.

Static modulus of elasticity
A high tensile modulus means that the composite is rigid and more stress is required to produce a given amount of elongation [26].
Compressive strength values were used for calculating static modulus of elasticity of the hard composite under consideration. The correlation between compressive strength and static modulus of elasticity of the different formulations at 28 days is shown in Fig. 4. It is clear from the scattering diagram that there was positive correlation between modulus of elasticity and compressive strength. Comparable results were published by Demirel [27] Following the regression analysis, equation of the curve is pointed as y = − 0.018x 2 + 1.412x + 0.372 where y assigned to compressive strength and x assigned to static modulus of elasticity, while the regression coefficient (R 2 ) = 0.995.
It is clear from Fig. 3 that, the highest modulus of elasticity has been reached from the CGC sample acquiring the highest compressive strength. The highest modulus of elasticity at 15% granite content can be due to the stiffness disclosed by the granite powders. On the other hand, the reduction in modulus of elasticity even by the more granite added, keeping the water added constant may be referred to incomplete hydration of the cement granite mixtures. This conclusion is in agreement with the previous published work for concrete products [28].
According to Niaki et al. [29], the analysis of the mathematical relations between the experimental data for compressive strength and the splitting tensile strength and between the compressive strength and the flexural strength of cementitious products display that they both comply with a power rule.
Accordingly, the stated study put forward the two coming equations to calculate the splitting tensile strength (fsp) and flexural strength (ff).
where fc is the measured compressive strength given in MPa.
Significantly, the two nominated empirical statements outfit a very near estimate to the experimental findings with reasonable negligible averages.
After the compressive strength-splitting tensile strength and the compressive strength-flexural strength, Table 8 nominated empirical relations, the proportions of the ff /fsp for the all granite ratios are nearly 2.8.
The decreases in the compressive strength of the resulting cementitious product with the raising the replacement of cement by the granite powder waste can be due to less binding effect [20].

X-ray analysis
The composition of the hydrate monoliths in percent were evaluated by Energy-dispersive X-ray spectroscopy (EDX). It is clear from Fig. 5 and Table 9 that the addition of granite powder led to increases in silicate hydrate contents (measured as Si) at the tested ratios of cement replacement.
The replacement of cement with granite powder up to 20% is raising the content of calcium hydrate (Ca), [30], On the other hand, raising the added G powder to 50% disposed to decrease in the (Ca) percent. At the high replacement ratio, i.e. 50%, the reduction in the (Ca) can be due to the increase in the amount of water required for G powder hydration and dominating a lower hydrate product in CGC, especially those due to Ca element. This can confirm and explain the reduction in mechanical integrity by escalating the granite powder contents Fig. 5 and Table 9.
It is obvious from the data, also, that there were increases in the concentrations of (Na), (K) and (F) which can attribute to the added G powder, (Table 1). TGA was performed for cement-granite composite to monitor the variation in mass loss of the composite as a function of temperature when subjected to high temperatures at a predetermined rate.
Decomposition of plain cement and CGC can happen in the course of TGA test and is generally differentiated into four main stages, Fig. 6. The first stage is related to the loss of free water in the temperature range from room temperature up to 271.6 °C.
The onset of second stage was 271.1 ended at near 450 °C and can assigned to the loss of water from hydrates (dehydration). The third stage associates with the dehydroxylation of Portlandite from ≈ 450 °C to 529 °C. The last stage correlated with decarbonation of CaCO 3 with onset 600 °C and ended above 700 °C. Figure 6 and Table 10 represent the TGA and DTA data obtained for the plain cement and cement granite composites had two ratios of granite powder and the impact temperature in plain cement and CGC during the thermogravimeteric analysis.
By the temperature rise from room temperature to more than 700 °C accompanied with a gradual degradation of the monolith items, resultant in a detectable changes in their mass due to the alteration in chemical composition and microstructure of the hardened products. At low temperatures, these changes are generally related to dehydration and water release. Near 100 °C the loss in mass is attributed to of surface water evaporation from the cement-based composite. Over 105 °C all free water evaporated. Starting from near 120 °C to approximately 500 °C evaporation of physically bound water contained in the small pores and capillaries is took place. At the same period, i.e. from ~ 150 °C (stability temperature of C-S-H gel) began the process of dehydration. Portlandite decomposed between 460 °C-540 °C. At range of 600 °C-700 °C a decomposition of the second phase of C-S-H and formation of β-C 2 S happened. Greater than 600 °C CaCO 3 aggregates decomposed into CaO and CO 2 . However, these processes are function of the compositions of the hardened items, temperature and pressure [30]. It is clear from Fig. 6, for plain cement (1) and cement granite composites (2 and 3), that there are two distinguishing endothermic peaks for each. The first ones, are broads in the temperature ranges from 75 to 270 °C centred at 163.37 °C, onset 75 °C endset near 250 °C centred at 166.22 °C and one started 75 °C ended about 243 °C had peak at 153.72 °C for plain cement and the CGC composite had 20% and 50% granite powder, respectively. These peaks can be referred to evaporation of surface water as well as part of bound water in addition to the dehydration of C-S-H, ettringite and calcium aluminate hydrate. The temperature at which these monoliths behaved is a function of the existing CaO: SiO 2 ratio in the hydrated matrices. The second endothermic effects, with narrow peaks at onset temperature in the range 445 °C to the endset at 529 °C have peaks near 480 °C. These distinguish the decomposition of Ca(OH) 2 formed during hydration in addition to part of bound water.

Bound water
The most extensively applied practice to measure the extent of reaction of plain cement or the CGC is the assessment of the bound water content derived from the mass losses of samples as a rule between more than 105 °C up the end TGA.
According to Bhatty [31] the chemically bound water is confirmed following the next equation where BW the bound water as a consequence of decomposition of CaCO 3 , MLdh mass loss due to the Dehydration phase, MLdx mass loss assigned to the Ca(OH) 2 (s) → CaO(s) + H 2 O (g) Dehydroxylation phase, MLdc mass loss related to the Decarbonation phase and 0.41 is a conversion factor.
The average values of bound water per gram of hydrated samples were 0.138 mg/g, 1.343 mg/g and 1.498 mg/g for plain cement, for CGC composite containing 20% granite and CGC had 50% granite, respectively, and all at w/c ratio: 0.40. It is obvious that the addition of granite as admixture to the OPC enhance the hydration reaction of the proposed composite. The application of G admixture can minimize water in composite formulations, with the potential enhancement in reducing "bleed" liquor.

Microstructure examination of plain cement and cement granite composite
The scanning electron microscopy (SEM) examinations for the microstructure of plain cement and CGC are presented in Figs. 7, 8, 9. Figure 7a-c shows the moistcured OPC paste after 28 days. It is noticeable that the hard specimen has a compact architecture Fig. 7a. The calcium silicate hydrate gel (C-S-H) is characterized by the presence of shapes varieties comprising foil-, flake, fibre-and tubular like [32]. Portlandite crystals (CH) have the prisms form and / or hexagonal plate like structure Fig. 7b. Very few Crystals of ettringite (E) are seen as needle-like structures Fig. 7c [33].
It was reported that the SEM examination for the used granite waste powder showed particles with varying sizes from nanometres to micrometres; they are crop up in aggregates/ agglomerates structures and are mainly rounded or angular in shape with slightly sharp edges [7]. Figure 8 shows that very little pores in the CGC sample containing 20% granite, Fig. 8a, with massive quantities of calcium silicate hydrate (C-S-H) and portlandite (C-H) which indicate the cement hydration reactions took place to an adequate level and resulted into passable dense matrix. It is noticeable that pores are miniature Fig. 8b. Figure 9 demonstrates a less dense composite containing 50% granite assembly, Fig. 9a, compare to the plain cement and CGC containing 20% granite. The C-S-H aggregated and other cement hydration ingredients, Fig. 9a. The pore contents are nearly more than that the same as the 20% composite, Fig. 9b. It is clear that the G powder stuck to the hydration ingredients to contract the pores. Figure 9c illustrates that the pores number of CGC are increased and the structure became loose. Based on the SEM examinations, it could be concluded that increasing the granite waste powder percentages had clear detectable deterioration impact on the architecture of the CGC under consideration at the  ratio 50%. The data obtained for SEM examinations confirmed the deterioration in the mechanical integrity the composite due to escalating the G powder percentages on the expanse of cement content in the CGC formulation. The reached data can, also, explain diminish in the mechanical integrity by increasing the granite concentration in CGC formulation.

Conclusion
The experimental data for this work confirmed that the addition of granite powder as partial replacement admixture for OPC can be applied for production of an inert composite with no sacrifice of physical and mechanical properties of the final monolith. However, to the up to date of our knowledge, no research has been reported on the use of granite waste as a component in cement composite formulation to acquire developed inert matrix can be applied for solidification/stabilization of some categories of radioactive wastes. Furthermore supplementary studies will be carried out to investigate the impact of freezing-thawing and immersion, for increasing periods and in different media, on the some thermal, physical and mechanical characters of cement-granite composite as a candidate inert matrix for immobilization of some categories of radwaste. Assessment of both radioactive wastes and granite scraps managements from the social and economical viewpoints should be considered besides the environmental impact.
As an alternative of searching a new cementitious product for stabilization solidification of specific radwaste, the suggestion of applying of waste granite powder in a newly developed cement granite composite not only aid to solve rising waste disposal crisis but also conserving the natural resources by serving to reduce the quarrying of cement.