Raw Material Cost per Block in Syria: Cement, Sand and Aggregate Share

Raw material cost per block in Syria is not a published figure anywhere. It is a multiplication you do on your own yard: the mass of cement, sand, gravel and water that leaves the mixer in one cycle, divided by the pieces that cycle produces, multiplied by the unit price you pay at your own gate. The machine only fixes the denominator. A QST1800 turns a 1,400 × 1,400 × 30 mm pallet in 15 to 25 seconds at 104 kW installed capacity, so it sets how many cycles a shift holds, not what the mix inside the mould costs.

Two blocks made on the same machine can carry very different material cost, and the difference sits in three places: how much cement the strength grade forces into the batch, how wet the aggregate arrives, and how many pieces survive from the press to the yard. Everything else is arithmetic. Machine parameters such as the 31.5 MPa rated pressure of the hydraulic presses or the 280 kN vibration force of the QST1800 describe how firmly a mix is compacted, not how much material goes into it.

How is the raw material cost per block in Syria assembled from your own figures?

The equation has one line per ingredient, each needing a mass and a unit price. Cement mass per block, sand per block, gravel or crushed stone per block, plus water and any admixture, each multiplied by what that material costs delivered to your yard. Mass per block is the batch your batching system discharges in one cycle divided by the pieces the mould produces in that cycle. Mould count is therefore a cost variable: the same frame carries 87 standard bricks of 240 × 115 × 51 mm per mould in one configuration and 12 hollow blocks of 390 × 190 × 190 mm in another, and those two moulds divide one batch in very different ways.

Write the equation once, then keep the two halves apart. The physical half, mass per block, is measured on your own scale and moves with mix design, mould wear and moisture. The price half moves with your supplier, your haul distance and the grading you accept at the gate.

What pushes the cement share of a block up or down?

The strength grade your buyer specifies is the first lever, and it is not yours to negotiate. A higher grade and a tighter strength tolerance push the mix designer toward more cement per cubic metre, and the block geometry decides how much of that cement the piece really needs. A solid 240 × 115 × 51 mm unit fills the whole section; a hollow 390 × 190 × 190 mm unit puts material into the walls and leaves the cores empty, so the same metered batch leaves the mould as a very different number of pieces.

The second lever is what you can substitute. Cement, sand, gravel, crushed stone powder, construction waste, slag, fly ash and gangue all sit in the raw material list of the QSGW line, and the crushing and screening circuit that prepares demolition concrete cuts off everything finer than 10 mm and returns recycled aggregate in several grades. Every tonne you replace is a tonne you do not buy, if the substitution holds the strength the buyer tests.

Sand, aggregate and moisture decide the mix you actually cast

Gradation is settled upstream. A QS-1200 twin-shaft mixer takes aggregate up to 80 mm for pebbles and 60 mm for crushed stone, so the crusher and screen circuit on your site sets the top size that can reach the mix, whatever the recipe says. Batching accuracy is the next control point: the PL series batcher stores the aggregate mix ratio, weighs each fraction on three-point load cells and vibrates the hopper against bridging, so the delivered mix matches the design mix.

Moisture is the correction most plants skip. Sand pulled from a bay after rain, or gravel straight off a wash screen, carries water that counts inside the batch. Unless you dry a sample and subtract, your cement weight is metered against wet aggregate mass, and every full point of moisture is paid for twice, in cement bought back and in blocks that fail the test. Dry a sample of each fraction and add only the water the mix still needs at the mixer.

Where do losses enter before the block reaches the yard?

Losses are pieces, not a percentage, and their place in the cost per block is pieces per shift. A cuber works at 15 to 18 seconds per layer and lifts 125 standard solid bricks or 18 standard hollow blocks in one layer, so a break at that station shows up in the shift total within an hour. Count the stations you can measure, and rebuild the count every time you change a mould or a material supplier.

• Press start-up: the first cycles after a mould change, while the mix settles and the fill depth stabilises.
• Green strength: breakage on the take-off conveyor and under the cuber clamp.
• Curing: corner damage during pallet lifting, finger car travel and stack building, plus pieces rejected after the strength test.
• Mould and pallet wear: worn liners change the piece dimensions and the fill volume.
• Mixer and batcher losses: material left in the mixer, spillage at the skip, and the dust the dust collector takes away.

How do you measure pieces per cycle and mass per piece on your own line?

Four readings do the job. First, the batch weights your batching system records: cement, each aggregate fraction and the water. Second, pieces per cycle, which you get by counting the mould cavities and confirming the count against the actual discharge, because a cavity can be blanked off. Third, the cycle time, measured with a stopwatch over twenty consecutive cycles at normal running speed; our machines are published in bands, such as 15 to 25 seconds on the QST1800, 20 to 25 seconds on the hydraulic presses and 13 to 18 seconds on the pallet-free series.

Fourth, mass per piece. Weigh a full pallet of cured blocks on a platform scale, subtract the pallet, and divide. Then dry three pieces to get the dry mass that is comparable with your recipe. Multiply pieces per cycle by cycles per shift to get the denominator of the whole calculation, and cross-check it against the shift counter. On a QST1800 that denominator can reach 220,000 standard bricks per 8-hour shift, and a configured QSGW line spans 30,000 to 250,000 pieces per 8-hour shift depending on the host machine, so a cost per block figure means nothing until the shift output behind it is measured.

Send your material sources, block sizes and strength grades

Tell us the block sizes you intend to sell, the strength grade your buyer specifies, and the materials you can actually get: sand gradation, top size of gravel or crushed stone, cement type, and any secondary material you want to use. Also send the pallet size you plan to run and the voltage and frequency you have at your site.

From those inputs we return a process recommendation: mould cavity count for each product, a cycle time target inside the published band of the machine class, the batching and mixing arrangement, and the curing and handling route that matches your target shift output. We do not quote one figure, because the material side and the site side are separate budgets, and only you hold the unit prices.